sometimes i get so tired of doing that. one day i was particularly lazy and didn't trim after pulling power way back for a descent. a buddy of mine was riding along in the actual for an observation flight. the captain i was flying with was a check airman and he tells my buddy, "we usually trim the plane up and dont fly sideways." so i throw some power in, the ball centers and i say, "im trimming it, see! look! its centered now." point is, its a plane. relax and just fly the thing and you'll be fine.