Admittedly it has got harder since Covid, however, I have found the secret is to look after those regulars and actively try and recruit new ones.
I give anything between 20%-25% discount on bookings of an hour or more to my regulars and I've found that they come back more frequently now, so I'm making more from them than I was before, even though they are giving me less for each booking.
I always make sure I give good service, give the client the full time they have paid for (I don't count showering as part of the booking) and don't make a fuss if there is a bit of slippage by 5-10 minutes. Admittedly you probably end up losing 90 minutes on a 60 minute booking but it keeps them coming back. I do stop boundary pushing once it gets too far though.
As for new clients who I've not seen before, assuming I want to see them again, then I always text them 15 minutes after they have gone saying what a good time we had and when I'm next available and would be great to see them again. Works wonders.
Just my view. I'm doing OK and make my target each week with ease, often doubling it, I only do this part time as well.