So, I'm finishing up my semi-home-brew physics engine, and there is a small amount of jittering when multiple shapes are stacked on top of each other. They go to sleep pretty quickly, but it's still there momentarily. I'm currently using debug-graphics (vector-graphics, really) so I can't really tell how visible this will be once I start using sprites instead.

Still, I'd just like to ask those of you have made your own physics-systems: how much jittering do you tolerate? How do you get rid of that last little bit (I've gotten rid of almost all of it... it really is very minor)?

To be clear, I'm not trying to create a be-all & end-all physics engine. This was somewhere between a pet project and a learning exercise and really just needs to perform basic game-style physics.

How do you get rid of that last little bit

Thought I don't use a home brew physics engine, I got rid of the last jitter by smoothing the rendering. This is, the rendered object does not copy the orientation of the physics model 1:1, but try to follow it using acceleration and damping, similar to what you would use in a multiplayer game.