You hit it on the head. Practice. That's the best way to improve. Don't try to think of something just to program, think of something that interests you. Do you like network apps? Try writing an IM clone, or just a simple chat utility with Java. Why not try to build a browser? Do you like security? Try writing an application that checks some various things on a UNIX system. Like games? Make Hangman, or Scrabble, or any of a thousand simple games. You don't have to create something original, just pick something that you like and try to recreate it in Java. That's a GREAT way to get some extra experience.