A pattern I seem to follow a lot.js

(function($) {
  
  $.fn.extend({
    pluginName: function(options) {
      // Initialise the class
      new PluginClass(this, $.extend({}, $.fn.pluginName.defaults, options));
      // Return this for chaining
      return this;
    }
  });
  
  $.fn.pluginName.defaults = {};
  
  var PluginClass = (function() {

    var self,
        element,
        opts = {};

    function init() {
      // Do stuff
    };

    return function(element, options) {

      self = this;
      element = element;
      opts = options;

      init();

      return this;
    };

  }());
  
}(jQuery));