I dont have a salon, but work from home and mobile. I find my most popular treatments are, in order:- waxing, tinting, mani/pedi, nail enhancements, facials & massage. Other treatments that are few and far between are: hopi ec, hot stones, ear piercing & make up.
I think it depends on your area a lot too, obviously high end treatments wont go down well in a less well off area.
HTH
Karaxxx