I did a Google search for 4th of July wreaths & I really loved this one. It was very simple (but a little time consuming) to make & only cost me $10!
You will need:
a straw wreath
red (which I already had), white & blue yarn
white wooden stars (or white paint if you can't find white stars)
hot glue gun
cardboard of some sort ( directions call for
matchbook but i used a toliet paper roll)
Check out The Creative Imperative for directions.