Call and make reservations ASAP! When we went in March last year I waited too long to call. I had a choice between 9:30pm on Friday night or 6pm on Sunday. I booked the Sunday evening. We were able to do a "walk in " Friday afternoon, but it would have been a lot nicer/ easier to have it booked for a set time, earlier in the day.
When you book they require payment in full, via credit/debit card for the cheapest package they offer (about $25). You can upgrade if you want when you get there. It is non refundable and if you need to cancel you have a year to use it or you can get products with the credit.
My daughter enjoyed the special treatment- however, watch the close! They will get a bit heavy handed with the make up if you dont make them be careful. My dd regrets going with the popstar make over, nd wishes she would have went with the princess makeover. I think we'll try that next time.