In general, I find that for videos the acting is more realistic.
Don't be afraid to look silly.
Some shows, like PPG, tape in a group session, which is always more fun because you can play off each other.
Start as early as you can. Make tapes of your characters.
I had to make squirrel noises as Bubbles and without realizing it, I was making the face and putting my fingers up to my face to look like a squirrel and everyone made fun of me for the rest of the day.
I usually have 10 different animation projects going at a time.