One of my regulars when he books always texts the night before asking if we are still on, then also morning of the booking which is usually in the afternoon then again about an hour before.
Drives me nuts. If I can't make it I will text him.
I have one like this, always "do you want to see me this week", "are we still on for today? Just let me know if you can't make it", "text me when you're on the way", "text me when you're on X tube line", "text me when you're at X station", "text me when you're five minutes away"?
I usually send an "on my way" text to new clients but I've never arrived late for a booking and I've only ever cancelled on this guy once because I was "ill" (I'd actually had a fight with my boyfriend and couldn't face the thought of seeing this guy in particular because of his clingy texting making me feel uncomfortable). This guy is actually completely fine in bookings but sends weird texts in between like "do you miss me?" and gets petulant if I ignore him (which I always do). Like honestly, this is my job, I don't want to engage with you all the time!