For starters, confirm whether your spa hotel has a policy in regards to dress code. You'll likely be supplied with a robe, slippers and a towel, but this isn't always the case. Underneath, aim to be as comfy as possible; tracksuit pants, yoga bottoms, T-shirts and sweatshirts are often recommended attire. Trainers and sports shoes are usually allowed, but restricted to dry areas only. It's also a good idea to bring another bathing suit and some extra clothing along.