Here are some basic tools that really help me with that:
- Quick rig scripts that let me setup basic structures (arms, legs...etc)
- Save/Load weights tool, so I can detach the skinning, make changes and rebind (even if point order changes).
- Orientation importer/exporter.. lets me change joint position and will maintain joint orientation (obviously the general orienation is preserved, in terms of what is the aim and up vector, but as the joint moves this stuff has to change). As long as the aim and up is correct, your animation will be preserved pretty well.
- Animation/Import export tool... lets me copy stuff in and out of different places really quickly.
That's it for now... I got some new art I'm working on that I'll post soon!