I learned this trick from my Mama just this year!
I lay most of my jeans out to air dry but I have one pair that is kind of stretchy and so I have to dry it otherwise it gets a little to big. The only problem is that when I dry it in the dryer the bottom cuff always rolls.
My boys cargo shorts do this too and we have a few pockets that like to dry puckered up. My Mom simply put clothespins on them before she put them in the dryer.