Hey, I did a rough demonstration on what I was thinking.
1- I selected these edges
2- Used the bevel tool
3- Used the subdivision modifier, I marked the places where I see most of the issues.
4- On the wireframe we can see that those places usually are where we have bad geometry. For this case, it seems that you have a character that is going to be animated.
I would advise you to do a retopology pass at least on this part, that way you’ll have a more responsive mesh. It may sound like pain in the ass but would help a lot on the rest of the project