Create a spa coupon book and sell them as gifts; this is great around the holidays. This idea goes beyond the gift card or gift certificate. This gives you a chance to create different themes. For instance you can have a book that is especially designed for pregnant moms that need a day of pampering or for teens who want to share a salon experience with some friends.  As an incentive, you can offer a discounted service to an existing client to entice them to purchase a coupon book.