For my daughter's 5th birthday, she had a Cinderella-themed party.
We made the invitations to look like royal proclamations sent out by a king, saying that the recipient was invited to attend a royal birthday celebration. When each girl arrived at the party, they were announced like royalty: "Presenting Princes Chrissy", etc. Then we gave the girls princess hats, which I had made out of regular cone-shaped party hats that I attached a long strip of color-coordinated fabric to. When the girls arrived they got to pick a hat and then decorate it with pretty stickers. While we waited for all of the guests to arrive, the girls worked on a mural. I had set up a big sheet of white butcher paper. To start things off I'd drawn a castle on the paper. The girls had fun adding their own drawings of princesses, flowers, rainbows, dragons, etc. We played games such as "Cinderella Where's Your Shoe" (just like "Doggie, Doggie Where's Your Bone"), a relay race (that consisted of chores like folding a towel, dusting a chair, putting on an apron), Pin the Nose on Gus (one of the mice from Disney's Cinderella movie), and then we had a piņata. I'd made it to look like the black cat on Disney's cartoon version of Cinderella. In the background during the party I had 'princess' music playing: songs from the various princess movies that the girls were familiar with. The cake was just a flat sheet cake that I had made & then decorated with purchased figurines of a coach, horses, pumpkins, a prince, and Cinderella.