Hi Debster - I Luuuurrrrrvvvveeee Spa's.
It depends on the type of spa & what package etc, but they are usually very relaxing places. People tend to wander about in bathrobes, sports wear, or loose clothing as it's usually warm. It involves lots of sitting about on couches or sun loungers & depending on facilities, jaccuzzi/sauna/steam room pool time. Take spare undies & swimming cossie if they have those as you may be in and out several times in the day.
The staff are usually very professional & should put you at ease and don't be afraid to ask, about anything. They should describe the treament before they start but you can ask if you want to know more & you can either chatter all the way through or chill out and enjoy in silence - it's up to you, it's your time.
Anything else, just ask. < drifts off thinking about spa time......>
