Wrists & Forearms: Any good tips?

It’s kind of strange that I see very little being said by others about this being one of the biggest problem areas, but wrists and arms have been one of the hardest things to smooth out in posing character models. Whether I use a single bone or 5-6 segments, turning the hand has a very small range before ugly twisting happens. It could be the topology is bad there, but this happens to a variety of models I’ve tried, both ones I created and some from Blendswap.

Does anyone have a success formula for this? I know shape keys can help, but I haven’t really gotten a handle on how to rig it up with drivers that use the same bone. I’ve been thinking of just rigging a more accurate bone structure, that uses two bones for the forearms, but that will probably also need some tricky constraints to rotate right. I wonder how many loops should be used, too. It seems the more there are, the more places for the arm to crinkle. Too few, and you can’t shape the arm very well. Nothing for it but a lot of painstaking weight painting, maybe?

My working time is limited, and spending a whole night testing different rigs isn’t the best way to use it if I can get any recommendations that point me in the right direction and cut down on the experimental time.

Topology must follow muscle flow to deform correctly.