Skin renews itself roughly every four weeks, which is where the monthly facial comes from. It is a good rhythm, but it is not a rule.
If your skin is calm
Every six to eight weeks is plenty. Spend the difference on a good cleanser and a sunscreen you will actually wear.
If you are working on something
Pigmentation, congestion and dullness respond to consistency. Three or four visits, three weeks apart, then stretch it out.
The best facial is the one that makes your home routine simpler, not longer.
What matters more
Sunscreen every day, a gentle cleanser and enough sleep will do more than any single treatment. We would rather tell you that than sell you a package.