Increasing image quality?

ive noticed a few people (pros) improving picture quality on crappy pictures..
mind sharing a few secrets?
thanks

Are you talking about increasing resolution? (ie: taking a 2"x4" photo and making it 10"x 20" without losing quality?)

-or-

Are you talking about taking a bad picture and making it look good? (ie: a picture with glare, a grainy picture, or some other photographic defect and reversing it)

I think he means the second option.

eya the second...