I've been in the process for making a game character to prototype a game with for a few weeks.
This is by far the most frustrating step in any part of making a game it seems. Everything is so unstable. I use an expression to drive forearm rotation, I have to remove it because it causes twitching and insane rotations. I have IK for my tongue and it breaks, I have to remove it.
Now I am making simplistic animations using basic IK arm, spine, and legs. The hands start rotating for no reason as they get translated. Is this my fault? Where do you learn how to do this properly? Is there a definitive source I can consult when making a run-in-the-mill biped rig? Why is this so hard?