A while ago, I did extensive googling to find some online pattern fitting help, and stumbled on Texas A&M University's Extension Service. There are a number of books (Fast Fit is pretty good) and websites (such as vintage sewing) out there dealing with fit but this is by far the best online source I've found. The diagrams show you an example of poor fit, wrinkles and all, and then give you the illustrated paper pattern piece solution.
Here are links to individual articles addressing fitting issues (they are pdfs). Please let me know if a link doesn't work.
Principles of Pattern Alteration
Personal Measurement Chart
Bodice Back Width
Lengthening and Shortening
Even Hip Circumference
Protruding Hip Bone
Back Hip Fullness
Location of Bust Fullness
Special Alterations for Pants (crotch depth, thigh circumference, large pones*)
Prominent Posture Problems
Upper Arm Sleeve Width
Increasing Bodice Front Fullness (FBA)
*I'm assuming "pones" refer to a body part, but the best my dictionary sources can give me is "cornbread" or "the player to the right of the dealer". If you have a problem with your cornbread, please refer to a cookbook.