Well the first thing you need to do is begin keeping a dream journal. Write down all your dreams, every detail...you can read more about this in the tutorials sections. After you have a dream journal you will be able to identify certain "dream signs"...like as you have said "jumping really high" or other signs, that occur in a majority of your dreams...some people's include being nude in public, or things that just aren't right...etc. Then once you recognize one of your dream signs when you are dreaming, do a reality check. There is a whole bunch of information on reality checks...but once you are at the point where you can actually do a reality check, you are probably already lucid because you are questioning the reality of your dream. Reality checks include...looking at a clock to see if the numbers change, trying to read (b/c its nearly impossible to read anything in a dream), holding your nose closed and trying to breathe is a favorite, trying to fly, etc. If you have any more questions, look through the tutorials or feel free to ask me or PM me.