A popular theme that works well for either a boy or a girl is a clown or other circus_related cake. They are usually very bright and colorful, which makes for instant attraction and a great focal point for a party table.
Animal Cakes: The younger set will especially enjoy a cake decorated to resemble their favorite animal. Kittens, puppies, pandas, and teddy bears are classic favorites. An easy way to decorate an animal_themed children's birthday cake is to use two round layers. Use the first round cake as the animal's head, and cut the second round cake to make ears and other features.