Heads up is a weird game, but a very good skill to develop. Raise your buttons or fold, never limp in the button. And pay attention to how deep stacks are. If stacks are deep, you can afford to see more flops, especially if you're better than your opponent.

Also, avoid calling all in pre- unless they are either really short stacked or you have a monster. Calling an all in is different than raising all in.