I get asked all the time how to get better at stand up comedy. Here's an answer in as few words I can muster...and you're probably not going to want to hear it.
First, you have to have some measure of talent for stand up, not everybody does, recognizing that in itself doesn't guarantee anything. Next you have to be prepared to work on your act, for hours... everyday, every waking moment if you have it. Write down ideas obsessively, search your soul and get to know yourself... everyday!