I almost always recycle my jeans into shorts!
I also like to reinforce buttons (they always feel so loose on new clothes!).
Several old band T-shirts have had the sleeves cut off and made into tank tops. I like to make crop-top T-shirts out of old shirts, too! I used to skateboard, so several of the older ones have holes from where I fell, but I like the design too much to let them go completely.