Cute and simple!!
Hot Glue Gun
Cut a piece of ribbon (this is the piece that will hang your ornament on the tree), fold it in half and use your hot glue gun to put a dot of glue about 1/2'' from the bottom.
Use hot glue to glue the ribbon unto the foam ball.
Put a dot of glue on the foam ball and glue a piece of wool.
Start wrapping the wool around the ball.
Don't forget.. you can use glue at any time to make sure the wool stays tight on the ball.
Glue buttons onto your ball.
You can use the buttons to cover where you might see glue dots.
P.S. I'll be linking to these Parties.