What kind of controls are you using? Aside from what's already been said, I teach to very slowly increase power and when you start to get some kind of lateral or fore or aft movement stop moving the collective/throttle neutralize the movement with the cyclic, and then start adding power very slowly again until you get another directional movement. Go slow. And how ever much you think you need to move the cyclic, move it less. Helicopters are very touchy and every input affects every other.