In order of how much they cost you to introduce:
- Reminders. Free, automatic, and they catch the people who simply forgot — which is most of them
- A written cancellation policy. Costs nothing, and it makes the conversation easier when it happens
- Deposits. Effective, but they will lose you some bookings from people who would have shown up
- Cancellation fees. The strongest signal, and the one most likely to end a client relationship
Most professionals over-reach for the last two before trying the first two. Turn reminders on and watch for a month before you decide you need a deposit.
If you do take deposits, say so plainly on the booking page. A surprise deposit at checkout is the thing that loses a first-time client.