The best way to land an appointment at the luxurious Aquanox Spa at Trump International Beach Resort is the old-fashioned way: just call the spa directly. Staff are friendly and happy to explain the many treatment options. Appointments and questions about treatments can also be addressed via the hotel’s website. (To book an appointment online, you must send your credit card number to hold a reservation.) The spa advises booking with as much notice as possible to secure your desired spot. As with most spas, weekends are busiest and weekdays, particularly early in the week, are considered quiet times.