Spa hotels are about relaxing and switching off from the real world, so pack clothes that are light, casual and easy to slip out of. T-shirts and yoga pants are a good choice. Slippers and robes are standard spa attire, but these are usually issued by the resort. Thinking of going for a dip in the pool or trying out a yoga class? Throw some workout gear, trainers and a swimming suit in your bag as well. If your hotel has an on-site restaurant, find out if it has a dress code — you may need to bring something fancy to wear to dinner.