Hips and shoulders are a real problem area, and the solution depends on the specific model.
However, here’s some things that can help
-Good topology is a must, otherwise you’re not going to ever make it look good.
-Experience helps, you will get better
-you can add corrective shapes to fix the things you just can’t get working otherwise.
(but get it as close as you can with straight skinny first)
-You can try using a lower mesh deformation cage instead of rigging the actual mesh
This can give better results
-then try the corrective smooth modifier after the armature modifier in the stack. Use a vert group to control the problem areas, rather than smoothing the entire model.
Hope that helps.
