(function($){
    $.fn.pluginName = function(options){
        var settings = {
            myFunction : function(){
                // If specified will allow the user to override it.
            }
        };

        if (options) {
            $.extend(settings, options);
        }
    };
});


// Will use default
$('selector').pluginName();

// Override
$('selector').pluginName({
  myFunction : function(){
    // overrides default
  }
});