There's nothing wrong with trusting your instincts first. That's what the great players do. I think where you go wrong is you can't BLINDLY trust your instincts; you should still evaluate the hand and present evidence to yourself to prove yourself right. If you can't seem to justify your initial instinct, you should then start to look at card equity, pot odds
One of my bad habits in tournaments is not keeping up the pace I know is needed to win. I'll hit a big hand and double or triple up, but then I'll get too "comfortable" and slow down. It always hurts me a few blind rounds later when I'm back to being a middle or short stack.