Just starting out.
Don't use motion tweens to do anything but horizontal motions. When an object rotates it must be redrawn, or it will look wrong.
Don't use silver gradiants(sp?) unless you absolutely must.
Silhouettes are cool but don't HAVE to be jet black.
Things that will make you better at a rapid speed:
Read Animators survival kit.
Do 5 still life drawings of a bar, spending no less than an hour on each.
Plan your colors out before you put them into your film.
Tween only when you must.
Keep animating,
It will only get more rewarding.