- Read the documentation.
- Familiarize yourself with the functions available. For example, know that there are different ways to find the parent of an element, such as parents() and closest(), and understand the difference.
- Learn how to chain your commands; most functions in jQuery return the same list of elements you started with, which means you can continue processing by simply tacking on more functions preceded by a dot, as in: $('div').addClass('selected').show();
- Understand when the document is finished loading and how to write code that safely access the elements only after the document is loaded. There are several ways to accomplish this.
- Learn CSS selectors. This is vital, because it's through CSS selectors that you use jQuery to locate your elements.
- Understand HTML best practices, and when to use IDs versus classes. (Yes, that's a separate issue from jQuery, but it impacts how you use jQuery.)