Animations in games are super important. They make the games look more interesting and the characters in them come alive.
One of the simple ways I do to quickly create an animation is by referencing another already made animation. For example the game I'm currently working on right now requires a cat playing the piano.
I couldn't afford the time to create a super high quality animation from scratch so what I did is to get an animation like this:
and then extract individual frames from this animated gif to base off my drawings. The resulting animation is this:
This looping animation of the cat playing piano comprises of 12 frames in total.
I create all frame-by frame animation using Flash CS3.
Each frame of an animation do not need to be perfect. The overall effect of the animation that gives it a fluid motion is more important.