A loyalty scheme fails when it is arithmetic the client never sees. If earning a reward takes a year and no one tells them how close they are, the programme is a cost, not a retention tool.
Make the earning rate obvious and the reward short. Spend a set amount, earn a point, redeem points for money off the next visit: three steps, no categories, no expiry games. Tie the scheme to paid sales so discounts never earn points twice.
Attach points to the client, not the visit. A client who moves between stylists should still see their balance, and a phone number is the key that makes that possible. That is why the POS keeps the loyalty balance on the client record and applies it at checkout.
Say thank you at the till. A short message after a paid sale, naming the client and the points they just earned, closes the loop and makes the balance feel real. Keep it warm and specific; a client who reads a receipt with their own name on it is more likely to return.