A fantastic look that is easily and inexpensively done: buy a bag of balloons from your local Dollar Store (chances are you already have them somewhere deep in that closet of everything). Next, cut off one quarter inch under the dangley part of the balloon. Take the leftover part, stretch it open, and insert the bottom of the glass cup in (this is best done with the help of a friend). If you can spare a couple of extra bucks, go out and purchase rounded bottom glass cups because the balloon with lie down perfectly without any creases or air pockets.
As features in Chatelaine: