I think I am in love with these tissue paper pom poms. The easy-to-follow instructions can be found at Martha Stewart's website (for some reason I can't get the link to work, so just search for pom poms in the wedding section). It's a cinch to change up the dimensions to make the pom poms different sizes. I found that the paper should be at least 1/3 longer than it is wide. The longer the paper, the fuller the pom pom (although be careful not to go overboard, or there will not be room to fluff all the layers).
With the help of a tall husband, we hung our pom poms over the food table, and they really looked lovely (and more fun than boring old balloons).
You can find another stunning example of how festive these look over at Oh Happy Day.