Look for this kind of fabric here.
Instructions: Cut your muslin into strips. Mine range from 3/4 in. - 1 in. wide. It really doesn't matter, however I will say the thinner strips lie more flat against the ornament. After you have your strips cut, apply hot glue to the ornament, attach the muslin strip, and start wrapping. Wrap until your ornament is covered and you are satisfied with the look. Put another line of glue on your ornament and attach the end of your strip. I tied the top of mine with jute string. You get to be creative here and can use any color of fabric and tie for the top. Here's a video showing how I wrapped mine.