Patience, practice and learning on your own mistakes. Read forums, see what other player writing and most important thing, learn to fold. Better is to lose one or two BB, than risk all with small hand.
Mostly skills come with experience. In live tournament itself never participated as expensive pleasure for me, I will not prompt. And online rather make sense to play micro limits than freerolls. I also advise you to watch the streams of poker and various events of live tournaments.
I believe that you can improve your game in several ways: watch textbooks and train, listen to professional advice and practice, watch games, professionals analyze your game, take into account good and bad things and play, play and play