or are you kinda fat? (not morbidly obese, just kinda fat with fat dangling around extra places)
if you are rail thin, then do infinite crunches and get in a muscle building diet.
if you are kinda fat... LOSE THE FAT FIRST. you can do all the crunches you want or sit ups but the abs will never show unless you lose the fat.
nah im kinda skinny, ill get a skinny comment here n there. and i am definitely not fat. i used to be chubby when i was younger. im about 5'8 140. i do have some flab around the waist (especially when i sit, maybe it has to do with my slouching), not like hanging, but it could use toning.
Something that I find helps a lot is if you can get in a gym, theres little stands that you can hold yourself up on, cross your legs some and slowly bring them up to a 90 degree angle..do that about 10 sets of 10 , also on a decline bench do sit ups but have a medicine ball, each time you go down touch the front and each side of your stomach with the ball. Then go back up..Do that like 3 sets of 20. on your last set go downa nd touch each side 25 times. Then go for a 20 minute jog. Takes a little while but you defiently see results in no time...and of coarse each right
Sit ups are not as effective as you think unless you do about 500+ a day. Try crunches on an exercise ball. You can get one for about 15 dollars at Kmart or somewhere.
The most effective ab exercises are the bicycle exercise and the captain's chair. The great thing about the bicycle maneuver is that you don't need any equipment. Just lay down on the floor. This burns the central abs as well the the obliques, giving you that "V-Shape" around the waist.
If you need to lose that layer of fat from the belly then do cardio first thing in the morning on an empty stomach or on a cup of black coffee or whatever. That will burn the fat a lot faster then doing cardio otherwise.