Check out these Craft Ideas Using Recycled T-shirts shared by the ThriftyFun community!
I made my daughter (age 5) a jumpsuit from my dad's old shirt. I didn't have a pattern, but I think it turned out OK. She loves it anyway.
Here is a video that shows how to turn a T-shirt into a no sew pillow. This is one of the projects I really enjoy.
This video shows a simple innovative idea to re-purpose a t-shirts into a cute halter top.