I did this project last year, but it was such a hit that I thought I would share it again. When we get together with family over the 4th of July I always try to plan a couple projects. Everyone brought a white tshirt to the lake and we painted them so we could all have matching shirts.
Start with a white shirt and some cardboard inside (so your paint doesn't seep through to the back).
Lay foam stars on top of the shirt...
Spritz tshirt paint on top... I bought these at Michael's.
Let it dry and you have a fun, patriotic shirt to wear.