Below are before and after shots of a skirt I altered (sorry they are a bit blurry, I need to invest in a better camera soon). I purchased it from a thrift store's "buy the pound" section at $1/pound, so it only cost a buck or two. My friend Yoonsin picked it out for me, and I hesitated to buy it at first since it seemed a bit long, as it fell a little past my knees. But at a dollar per pound, I couldn't resist -- I am frequently looking for new sewing projects anyway.
It doesn't look like I altered it in the photo, but months after picking it up, I finally shortened the skirt a couple inches and used the extra material to make two front pockets. (If the pockets are hard to see, click the image to enlarge it for more detail.)