Help removing huge waist

So, I started creating clothes. I have no experience using photo shop and downloaded the free gimp program. I picked up on it really fast and started making myself some really nice outfits. The only problem is that I couldn't figure out how to remove the huge waist on the skirts. i got so frustrated trying to figure it out that i quit making clothes LOL. So, finally I've decided to ask for some answers/hints/clues on how to do that.
Thanks alot, I'd apreciate any responses or links to answer threads.

There is not much you can do with the fat ass skirt problem. Most people just shrink their waist and saddle area on their avatar to make the skirt look okay.

You can of course make skirts out of prims or combination of prims and texture. Some of the tight skirts are made from pants and a prim in the crotch area to simulate a skirt. If you are making a poofy skirt, its just mostly prims as attachments.