You can purchase a doll "top" for this purpose or just pull a dolls legs off, like I did. I found the doll in a craft store (apparently it's meant for you to crochet some clothes for it...ha!) and I used a 40% off coupon, making it a mere $1.80 topper.
I did a crumb coat and then frosted it with homemade white buttercream frosting. I was planning to just accent with sprinkles, but couldn't figure out how to do it easily. So, the whole thing got coated in blue crystals. The bodice of her dress is just icing and sprinkles, like the cake.
The castle cake is 2 8-inch square cakes stacked. The corners are ice cream cones--one upside down and the other on top. I should have baked four with cake mix inside, but I didn't. So, I put a giant marshmallow inside, another 1/2 on top of that and then filled the top with frosting. I notched the corners so the cones would set in. Then, we used mini mallows on top and sugar wafer cookies for doors and windows.
(Asa was being silly and, at the prodding of a friend, stuck a horse in the castle.)
The wands are star shaped foam hot glued to a dowel. The girls put foam stickers to decorate, then we tied curling ribbon on the bottom. We had glitter glue but realized it was crazy messy and ditched it. It also takes too long to dry for using at a face-paced party.
The crowns are sparkly wire with curling ribbons attached at the back.
The swords are from Target's $1 bins. (Yay for dollar bins!)
The shields are cut cardboard wrapped in gold wrapping paper with handles made from duct tape. They were done completely by Joel. I cut out some shapes (including a fleur de lis I got online) from foam and the kids glued those on. They also used masking tape to make stripes.
The pinata came from WalMart and is really labeled as a T-Rex. Some construction paper wings and flames from his mouth (made by Joel) transformed him into a more fierce beast.
Lunch (never pictured) included peanut butter and jelly sandwiches and tuna sandwiches--cut small, turkey tortilla wraps, chips, chex mix, and grapes. We served fruit punch and water.
Along with cake, we had some "magic wands" on the table -- large pretzel rods dipped in white chocolate and covered in blue sprinkles.
Joel made the invitations (he uses Publisher), and we had them printed as 4x6 pictures.
To decorate and make our home more festive, I hung blue streamers, made some flags from construction paper, and hung lots of balloons from the ceiling. Balloons and streamers are a very inexpensive way to pack some punch. You do NOT have to use helium. Everyone commented on the balloons and it was 4 $1 packs attached to the ceiling using $1 of curling ribbon. Easy and fun.