Hi Lisa!
In December I had a "princess party" for my 3 year old. I sent an evite, but you could send a written one as well that read. "By Royal command all Prince and Princess's are invited to a birthday ball" Castle: insert address Given by" Queen Lisa and King (insert name) and Royal attire welcomed, in parenthesis I said can wear princess dresses if they would like. I am going on memory, but you get the idea of the invites.
Some of the girls came in dresses and I had a little craft table set up with gems bought from AC moore and foam crowns and tiara's for the kids to decorate.
There is a spectacular castle cake mold (the 3d one) in the wilton isle if your crafty. Being December I had no time to do it. If thats not your thing, take a picture of cinderella and have it lazered on a cake.
If I think of anything else I did I will post again!
Kelly
arty: