Do you own any books or collection DVD sets? If you do, and have read them, and still have this question, then I would recommend picking up some of Mark Wilson's work. The force is, in my opinion the single most useful concept in all of magic. It's applications are infinite, as you are only limited by your imagination (which is an infinite resource).
Oh and don't knock dupes. If used properly, they are devastating. But truly, I do not know what you mean. Explain if you'd like.