var img = new Element("img", {
src: 'myimage.jpg',
'class': 'galleryimg',
alt: 'Check out this image'
});

Nicer than:

var img = $("<img /">).attr("alt", "Check out this image").attr("src", "myimage.jpg").addClass("galleryimg");

MooTools is the first one. I love it! If there is a nicer way to do it in jQuery (I can’t find one but I have a feeling there should be) then please let me know!

(function($){
	$.fn.pluginName = function(options) {

		var
		  defaults = {
		  	//here you should set your default options.
			//example: backgroundcolor: red
		  },
		  settings = $.extend({}, defaults, options);

		  this.each(function() {
		  	var $this = $(this);
			//now use $this instead of $(this), makes jQuery do less work

		  });
		  // returns jQuery which allows for chaining
		 //eg $('div').yourPlugin().hide();
		  return this;
	}
})(jQuery);