List Posts By Category: Custom page template to grab all categories and create an un-ordered list of posts within each. Page template create for Genesis, but could be adapted to any WordPress theme. http://oncecoupled.com/2014/06/13/page-template-list-posts-by-category/

page_category_index-2.php

<?php
/**
 * Template Name: Category Index
 * Created By: Lauren Gray Designs
 * URL: http://oncecoupled.com
 */
 
 /* Exclude categories: */
 	$args = array(
		'type' => 'post',
		'orderby' => 'name',
		'exclude' 	=> array(3,52,125,133,663,745),
		);

page_category_index.php

<?php
/**
 * Template Name: Category Index
 * Created By: Lauren Gray Designs
 * URL: http://oncecoupled.com
 */

// Remove the loop and replace it with our own
remove_action( 'genesis_loop', 'genesis_do_loop' );
add_action( 'genesis_loop', 'LGD_add_archive', 9 );

function LGD_add_archive() {

	$args = array(
		'type' => 'post',
		'orderby' => 'name'
		);
		
	$categories = get_categories($args);
	
	// List each category
	foreach($categories as $category) { 
	
		// Output the cateogry (and link to it)
		echo '<ul><li><h3><a href="' . get_category_link( $category->term_id ) . '" title="' . sprintf( __( "View all posts in %s" ), $category->name ) . '" ' . '>' . $category->name . '</a></h3><ul>';
		
		$args = array(
			'posts_per_page' => -1, 
			'category' => $category->term_id );

		$myposts = get_posts( $args );
		
		// List the posts in said category
		foreach ( $myposts as $post ) : setup_postdata( $post );
		echo '<li><a href="' . get_permalink($post->ID) . '">' . get_the_title($post->ID) . '</a></li>';
		endforeach; 
		
		// Close everything up
		echo '</li></ul></ul><br><br>';
	}
}

genesis();