For my daughters 5th birthday, we had a spa/salon theme. The  invitations were on white card stock, with black drawings, wording and border and piped in hot pink.  I designed them to look like two "funky"  girls in bath wraps (which consequently matched the party favor) and it  read "Are you tired of the same old look?  Do you want to have some  fun?  Join Mimi for giggles and glamour at the Birthday Spa/Salon".    Below that it said "Call to confirm your appointment" and listed our phone number.  My daughter invited 3 other friends (two her age and one that was in high school!!) and we met at a local beauty salon after hours for the  "private appointment.". There they were given  bath wraps. I'd bought some adorable white pillowcases with 3 large flowers on them.  A friend lined them with a white towel and they tied over tho girls  shoulders with white grosgrain ribbon. They were given the royal treatment. Their hair was washed and then rolled in big curlers. They then sat under the dryers while their hair set.  During this time they had "spa food".....chicken salad, chococlate covered strawberries (made to look like tux's) and rolls.  There were  also small petifores that were each decorated individually in bright colors with swirls, flowers, stripes, polka dots, etc. In addition to eating, they also thumbed through various fashion magaizines.  Next they each got their hair styled and make up and nails done.    Overall, the spa/salon cost me $100 for the four of them and the party  lasted over 2 1/2 hours.  The girls thought they looked fabulous and they all had a great time.   For thank you notes, I included a picture of before and after shots of the girls. They all enjoyed it. The girl in high school (who'd been her baby sitter and was such a good sport for coming) did a version of my  daughters party (only added massages) for her 16ith birthday party.