We went with a Thomas the train theme since our son loves to play with Thomas the train. We ordered a Thomas the train cake kit on-line and bought a plain vanilla sheet cake and a tub of blue icing from a grocery store. It was very easy to follow the directions in the cake kit.
We cut the pieces as directed, iced each one after we added it on and then piped on the details. The pieces from the kit fit perfectly and were very easy to assemble. We found the little train candle holders on-line.
We got a lot of compliments on the cake at the party! Since we had so much extra icing, we also made cupcakes and cookies. We also bought the Thomas the train birthday figures, cupcake rings, Thomas pinata, plates and napkins on-line. We bought the Thomas the train balloon and the other big balloon at a party store.
We filled the pinata with toys (little play doughs, bouncy balls, mini rubber ducks, etc.) instead of candy. For favors we gave kids Thomas the train books, puzzles and stickers.