This is what I use:
Round cookies with holes
Red royal icing (soft consistency)
Green royal icing (soft consistency)
Round tip 2 or 3 for the red icing
Leaf tip medium size for the green icing
Pipe the green royal icing leaves on the cookie. Starting from the inside of the cookie working your way around the wreath. Set aside to dry.
Pipe small red berries randomly on the wreath and set aside to dry completly.
Voila! A nice Christmas wreath cookie for you to enjoy.