I have problems with fingers in general but this is the hardest part for me.
It looks ok at this point:
But if I rotate at the base of the finger, problems start:
This is because the rotation point should be around the middle of the knuckles, at least that's what I think:
I changed the bones to rotate from that point, but I really can't achieve a good look. Any tips? I have no idea how to make any significant improvement. That whole knuckle area that connects to the fingers rotates too, but I'm not sure how I can make it rotate and deform correctly.