I do a combination of dollar tree and online.
Birthdaydirect is a good website. I usually do a google search for birthday supplies for whatever character I want and try to find the best price online. They I get party favors, plates, cups, plasticwear, hats, streamers and balloons at dollar tree.
Good luck and have fun.
Remember, the plates, cups and plasticwear don't really need to match. Get a balloon with the characters, cake decorations, piñata, tablecloth and centerpiece. Everything else you can find a dollar tree. (of course, you can get everything at the website and spend more if you want :-) )
at 3:12 PM on Jan. 28, 2011