Whatever the theme of your party, you can decorate it to the max with supplies from the party shop.
They carry a wide variety of invitations, decorations, paper goods, and favors for any sort of party. Most of it is very reasonably priced. One highlight is the plastic punch bowls and such which can be difficult to find in plastic and expensive; they really do look like glass. Some party supplies vary seasonally while others are constant. The range of colors of paper goods is fantastic. I certainly drop by any time I throw a party, or even just to browse - the staff is fantastic about that.