Chain stores and catalogs are a great place to scout out affordable homewares, but like shopping for clothes at Gap and H&M, you can run into the problem of having the same cool stuff as everyone else. So take a page from petite women who buy kids' clothes and shop the kiddie offerings at your favorite home stores.
Retailers such as Pottery Barn's PBTeen and Ikea carry some surprisingly hip items that, taken out of context, don't look childish. I like to look for lighting rugs and accessories like this the Pottery Barn Kids Primary Countertop Accessories ($9-39) from the Dr. Seuss collection.
It may not be as cheap as getting your clothes in the kids' section, but at least it's unexpected.