Where to start? What competition? Take pretty flower pictures? Nude portrait? Ants? Sky? People? Garbage in, garbage out.
This topic could fill several books, or be summarized in two sentences:
Nobody can teach you the creativity that you would need to take a picture that stands out from the rest. It is only you and your camera that can make the difference, and if you think you need people to teach you that, then you have already lost the competition.
But my suggestion would be look for those photo that wins competition, try to isolate the elements that makes the photos stand out from the rest. However, this could make your photos lost creativity, if you tend to follow other's style.
there is nothing wrong in feeling angry or pissed with yourself if you do not win a competition; but one should move on quickly enough.
there is nothing wrong in feeling happy for winning one, but one should realise that it is just one, and after a while accolades of that sort mean little to anyone else but the ones that you really shouldn't care about, i.e. people too enamoured with 功名..
taking competitions seriously enough to shoot well, yet not to the extent where you just crash and burn when you do not win anything.. that is the way to go.
some of the world's best photographers have not won a single award their entire life.
in singapore, ken seet has won nothing that i can think of, but he has the respect of many good photographers. doesn't that say a lot?