Taking a trip to a spa hotel is about relaxing and unplugging from the real world, so take clothing that is casual, loose-fitting and easy to slip out of. Sweatshirts and tracksuit pants are great options. Slippers and robes are common spa attire, however these are usually issued by the hotel. Thinking of going for a swim or limbering up with a yoga class or two? Toss some workout gear, trainers and a swimming suit into your suitcase as well. If your hotel has an on-site restaurant, find out if there's a dress code — you may need to bring something stylish to wear to dinner.