As a person who values the work done by your hairdresser, a thoughtful tip is always appreciated during the holiday season. Typically, a tip of 15-20% of the total cost of your service is considered appropriate. However, the amount you ultimately decide to give should be based on your personal experience and satisfaction with the service provided. Remember to take into account factors such as the quality of the haircut, the time spent on the appointment, and any extra services provided.