What's the best way to make your character bend its arm at the elbow? Divide into three parts? Bone? I currently have the arm divided into two symbols and they each have a motion, but there is a gap where there should be an elbow.
The best way I've found to work is to use three symbols. One is the forearm, the other is the bicep and the third is an oval for the elbow which patches the gaps. It's far from perfect though and many animators create another layer called the Patch layer whereby they hand draw the parts that are missing frame by frame. The elbow symbol helps a lot though. Here's an example of what I mean.