Given you'll probably spend a good deal of your time in a plush bathrobe and slippers, you won't need to take a lot. Besides comfy, loose-fitting clothes to change into after your pampering treatments, personal items such as underwear and deodorant should be at the very top of your packing list. Of course, if you intend to make use of the pool or try out an exercise class or two, throw a swimming suit and some gym gear into your bag too. Finally, leave the electronics behind and take a good book instead. It is a relaxation trip, after all.