Gruntfile.js inspired by Yeoman's webapp generated Gruntfiles, with BlessCSS and Assemble, Htmlmin configured to run smoothly with Usemin and Coffee/Mocha stuff commented out.

Gruntfile.js

// Generated on 2013-07-30 using generator-webapp 0.2.6
'use strict';
var LIVERELOAD_PORT = 35729;
var lrSnippet = require('connect-livereload')({port: LIVERELOAD_PORT});
var mountFolder = function (connect, dir) {
    return connect.static(require('path').resolve(dir));
};

// # Globbing
// for performance reasons we're only matching one level down:
// 'test/spec/{,*/}*.js'
// use this if you want to recursively match all subfolders:
// 'test/spec/**/*.js'

module.exports = function (grunt) {
    // load all grunt tasks
    require('matchdep').filterDev('grunt-*').forEach(grunt.loadNpmTasks);

    // configurable paths
    var yeomanConfig = {
        app: 'app',
        dist: 'dist'
    };

    grunt.initConfig({
        yeoman: yeomanConfig,
        watch: {
            // coffee: {
            //     files: ['<%= yeoman.app %>/scripts/{,*/}*.coffee'],
            //     tasks: ['coffee:dist']
            // },
            // coffeeTest: {
            //     files: ['test/spec/{,*/}*.coffee'],
            //     tasks: ['coffee:test']
            // },
            compass: {
                files: ['<%= yeoman.app %>/styles/{,*/}*.{scss,sass}'],
                tasks: ['compass:server']
            },
            livereload: {
                options: {
                    livereload: LIVERELOAD_PORT
                },
                files: [
                    // '<%= yeoman.app %>/*.html',
                    '<%= yeoman.app %>/**/*.hbs',
                    '{.tmp,<%= yeoman.app %>}/styles/{,*/}*.css',
                    '{.tmp,<%= yeoman.app %>}/scripts/{,*/}*.js',
                    '<%= yeoman.app %>/images/{,*/}*.{png,jpg,jpeg,gif,webp,svg}'
                ],
                tasks: ['assemble', 'bless:server']
            }
        },
        connect: {
            options: {
                port: 9000,
                // change this to '0.0.0.0' to access the server from outside
                hostname: 'localhost'
            },
            livereload: {
                options: {
                    middleware: function (connect) {
                        return [
                            lrSnippet,
                            mountFolder(connect, '.tmp'),
                            mountFolder(connect, yeomanConfig.app)
                        ];
                    }
                }
            },
            test: {
                options: {
                    middleware: function (connect) {
                        return [
                            mountFolder(connect, '.tmp'),
                            mountFolder(connect, 'test')
                        ];
                    }
                }
            },
            dist: {
                options: {
                    middleware: function (connect) {
                        return [
                            mountFolder(connect, yeomanConfig.dist)
                        ];
                    }
                }
            }
        },
        open: {
            server: {
                path: 'http://localhost:<%= connect.options.port %>'
            }
        },
        clean: {
            dist: {
                files: [{
                    dot: true,
                    src: [
                        '.tmp',
                        '<%= yeoman.dist %>/*',
                        '!<%= yeoman.dist %>/.git*'
                    ]
                }]
            },
            server: '.tmp'
        },
        jshint: {
            options: {
                jshintrc: '.jshintrc'
            },
            all: [
                'Gruntfile.js',
                '<%= yeoman.app %>/scripts/{,*/}*.js',
                '!<%= yeoman.app %>/scripts/vendor/*',
                'test/spec/{,*/}*.js'
            ]
        },
        // mocha: {
        //     all: {
        //         options: {
        //             run: true,
        //             urls: ['http://localhost:<%= connect.options.port %>/index.html']
        //         }
        //     }
        // },
        // coffee: {
        //     dist: {
        //         files: [{
        //             expand: true,
        //             cwd: '<%= yeoman.app %>/scripts',
        //             src: '{,*/}*.coffee',
        //             dest: '.tmp/scripts',
        //             ext: '.js'
        //         }]
        //     },
        //     test: {
        //         files: [{
        //             expand: true,
        //             cwd: 'test/spec',
        //             src: '{,*/}*.coffee',
        //             dest: '.tmp/spec',
        //             ext: '.js'
        //         }]
        //     }
        // },
        compass: {
            options: {
                sassDir: '<%= yeoman.app %>/styles',
                cssDir: '.tmp/styles',
                generatedImagesDir: '.tmp/images/generated',
                imagesDir: '<%= yeoman.app %>/images',
                javascriptsDir: '<%= yeoman.app %>/scripts',
                fontsDir: '<%= yeoman.app %>/styles/fonts',
                importPath: '<%= yeoman.app %>/bower_components',
                httpImagesPath: '/images',
                httpGeneratedImagesPath: '/images/generated',
                httpFontsPath: '/styles/fonts',
                relativeAssets: false
            },
            dist: {},
            server: {
                options: {
                    debugInfo: true
                }
            }
        },
        bless: {
            server: {
                css: {
                    options: {
                        cacheBuster: false,
                        compress: false
                    },
                    files: {
                        '.tmp/styles/main.css': '.tmp/styles/main.css'
                    }
                }
            },
            dist: {
                options: {
                    cacheBuster: false,
                    compress: true
                },
                files: {
                    '<%= yeoman.dist %>/styles/main.css': '<%= yeoman.dist %>/styles/main.css'
                }
            }
        },
        // not used since Uglify task does concat,
        // but still available if needed
        /*concat: {
            dist: {}
        },*/
        requirejs: {
            dist: {
                // Options: https://github.com/jrburke/r.js/blob/master/build/example.build.js
                options: {
                    // `name` and `out` is set by grunt-usemin
                    baseUrl: yeomanConfig.app + '/scripts',
                    optimize: 'none',
                    // TODO: Figure out how to make sourcemaps work with grunt-usemin
                    // https://github.com/yeoman/grunt-usemin/issues/30
                    //generateSourceMaps: true,
                    // required to support SourceMaps
                    // http://requirejs.org/docs/errors.html#sourcemapcomments
                    preserveLicenseComments: false,
                    useStrict: true,
                    wrap: true
                    //uglify2: {} // https://github.com/mishoo/UglifyJS2
                }
            }
        },
        rev: {
            dist: {
                files: {
                    src: [
                        '<%= yeoman.dist %>/scripts/{,*/}*.js',
                        '<%= yeoman.dist %>/styles/{,*/}*.css',
                        '<%= yeoman.dist %>/images/{,*/}*.{png,jpg,jpeg,gif,webp}',
                        '<%= yeoman.dist %>/styles/fonts/*'
                    ]
                }
            }
        },
        useminPrepare: {
            options: {
                dest: '<%= yeoman.dist %>'
            },
            html: '<%= yeoman.app %>/index.html'
        },
        usemin: {
            options: {
                dirs: ['<%= yeoman.dist %>']
            },
            html: ['<%= yeoman.dist %>/{,*/}*.html'],
            css: ['<%= yeoman.dist %>/styles/{,*/}*.css']
        },
        imagemin: {
            dist: {
                files: [{
                    expand: true,
                    cwd: '<%= yeoman.app %>/images',
                    src: '{,*/}*.{png,jpg,jpeg}',
                    dest: '<%= yeoman.dist %>/images'
                }]
            }
        },
        svgmin: {
            dist: {
                files: [{
                    expand: true,
                    cwd: '<%= yeoman.app %>/images',
                    src: '{,*/}*.svg',
                    dest: '<%= yeoman.dist %>/images'
                }]
            }
        },
        cssmin: {
            // This task is pre-configured if you do not wish to use Usemin
            // blocks for your CSS. By default, the Usemin block from your
            // `index.html` will take care of minification, e.g.
            //
            //     <!-- build:css({.tmp,app}) styles/main.css -->
            //
            // dist: {
            //     files: {
            //         '<%= yeoman.dist %>/styles/main.css': [
            //             '.tmp/styles/{,*/}*.css',
            //             '<%= yeoman.app %>/styles/{,*/}*.css'
            //         ]
            //     }
            // }
        },
        htmlmin: {
            dist: {
                options: {
                    removeCommentsFromCDATA: true,
                    // https://github.com/yeoman/grunt-usemin/issues/44
                    // collapseWhitespace: true,
                    collapseBooleanAttributes: true,
                    removeAttributeQuotes: true,
                    removeRedundantAttributes: true,
                    useShortDoctype: true,
                    removeEmptyAttributes: true,
                    removeOptionalTags: true
                },
                files: [{
                    expand: true,
                    cwd: '<%= yeoman.app %>',
                    src: '*.html',
                    dest: '<%= yeoman.dist %>'
                }]
            },
            deploy: {
                options: {
                    collapseWhitespace: true
                },
                files: [{
                    expand: true,
                    cwd: '<%= yeoman.dist %>',
                    src: '{,*/}*.html',
                    dest: '<%= yeoman.dist %>'
                }]
            }
        },
        // Put files not handled in other tasks here
        copy: {
            dist: {
                files: [{
                    expand: true,
                    dot: true,
                    cwd: '<%= yeoman.app %>',
                    dest: '<%= yeoman.dist %>',
                    src: [
                        '*.{ico,png,txt}',
                        '.htaccess',
                        'images/{,*/}*.{webp,gif}',
                        'fonts/*'
                    ]
                }, {
                    expand: true,
                    cwd: '.tmp/images',
                    dest: '<%= yeoman.dist %>/images',
                    src: [
                        'generated/*'
                    ]
                }]
            }
        },
        concurrent: {
            server: [
                'compass'
                // , 'coffee:dist'
            ],
            test: [
                // 'coffee'
            ],
            dist: [
                // 'coffee',
                'compass',
                'imagemin',
                'svgmin',
                'htmlmin:dist'
            ]
        },
        bower: {
            options: {
                exclude: ['modernizr']
            },
            all: {
                rjsConfig: '<%= yeoman.app %>/scripts/main.js'
            }
        },

        assemble: {
            options: {
                flatten: true,
                layout: '<%= yeoman.app %>/templates/layouts/default.hbs',
                partials: ['<%= yeoman.app %>/templates/partials/*.hbs']
            },
            pages: {
                files: {
                    '<%= yeoman.app %>/': '<%= yeoman.app %>/templates/pages/*.hbs'
                }
            }
        }
    });

    grunt.loadNpmTasks('assemble');

    grunt.registerTask('server', function (target) {
        if (target === 'dist') {
            return grunt.task.run(['build', 'open', 'connect:dist:keepalive']);
        }

        grunt.task.run([
            'clean:server',
            'concurrent:server',
            'connect:livereload',
            'open',
            'watch'
        ]);
    });

    grunt.registerTask('test', [
        'clean:server',
        'concurrent:test',
        'connect:test'
        // , 'mocha'
    ]);

    grunt.registerTask('build', [
        'clean:dist',
        'useminPrepare',
        'concurrent:dist',
        'assemble',
        'requirejs',
        'concat',
        'cssmin',
        'uglify',
        'copy:dist',
        'bless:dist',
        'rev',
        'usemin',
        'htmlmin:deploy'
    ]);

    grunt.registerTask('default', [
        'jshint',
        'test',
        'build'
    ]);



};