I saw quite a few different ways to extend jQuery, e.g. through jQuery.extend(), jQuery.fn.extend(), $.extend(true, $[ Namespace ][ pluginName ].prototype, extensionMethods), etc.
Could you post a template that you recommend using for extending jQuery?
The different extension points are used for different purposes. Extending jQuery.fn creates a function that operates on a collection of DOM elements resulting from a selector or traversal process, such as graphical sliders, datepickers, etc. Extending jQuery directly allows you to create utility or function plugins that don't work on DOM elements directly, e.g. the cookie plugin. jQuery includes many other extension points as well - for selectors, for animations, for ajax processing, etc. These are all covered in the book.
I use my own plugin framework unless I'm specifically writing a jQuery UI widget in which case I use the Widget framework.