One of the best ways to keep clients coming back to you is to add a few minutes to their massage hour.
They are paying you per minute, for you time. If you add just 1-4 minutes, it's great for their neck, hands or feet, and they will love it.
Sometimes you could even let them know, "Are you in a rush today? I was going to add a few minutes so I can focus a bit more on your neck, or would you rather I end on your hand?"
Schedule 15 minutes, at least, in between each client to allow for time to change sheets, take payments, reschedule and let the next client get ready.
The only time clients can be scheduled back to back is when you only have 2. This way, if you start your next client a few minutes late, which you will, then you can go over a few minutes and not create a traffic jam of waiting clients.
Don't short your clients! This is the worst business practice in our massage profession. Have integrity about your time. If you have to short them at some point, let them know that you are aware of stopping early and offer to give them more time for their next massage.
If it's a new client, then discount the massage. Keep the practice that "the client is always right".
When you "take the hit" of a client discount and/or less money for a short massage, or a treatment you were late to, too tired/hungry to do your best, etc, a few dollars less is worth their loyalty. They will appreciate the gesture, and in most cases will tip you more, or if not a tip, at least will remember your integrity. Respect their time & money.
A few minutes of your time given as a gift will return to you with much more abundance.