ask the spa if they have a mailing list,or go to their website and sighn up for it there.
Often spa’s will send out coupons through the mail and email for deals during the slower times of the year. Those services are conditional during certain days/times etc but they are much cheaper than regular times of the year. Also call for specials ahead of time. Often there are specials not advertised on their inside bullatin board or website that are conditional offered that day or week only for walk ins when buisness is really slow
(like after christmas) typically these deals are first come first serve and require prepayment. Also take advantage of the sauna/whirlpool/relaxation room and snacks while you are there if they are included free with the visit. and if you liked a certain product don’t be afraid to ask for a sample or if there are any discounts on that item. Sometimes you can get a discount if you purchase a certain amount of products the same day you get your services. Often spa personnel try to upsell this but sometimes they forget or its upon request only…SO ask,it never hurts to ask!

Also come early and leave late, when you get your shower etc,before or after your treatment they let you use their shavers,their shampoo/conditioner,body wash/lotions/etc etc etc. This is a great way to pamper yourself before pampering,plus you can stay in their shower as long as you want without worrying about your water bill going up(this is why I like my ultra clean showers at the gym to,I hate high water bills)