Use some of the pipe insulation tubing.
This is the stuff that you cover your water pipes with to protect from freezing or sweating (depending on where you live)
It comes in 3 ft lengths and is basically foam tubing. I use it with a wire framed wreath that I hang on my house for Christmas decorations. Just cut 3 inch pieces, rip it open along the cut line and then use the 'handy man's helper' duct tape to hold it back together.
Hope this helps.........