I have a full-time civvy job, so only escort a fews times a month.  I only take advance bookings, and only make outcalls.  I also only do longer bookings as one hour appointments weren't really worth the time or effort  - it took longer to get ready/travel to them than the appointment length itself. 

I only see regulars now too, so no longer advertise, but my website is still live.  This has majorly cut down the number of (new/useless) enquiries I get, and those I do, go to an inbox I rarely check. Also, and as a plus, as I do have such limited availability, none of my clients muck me around, and if they do, they go out of their way to compensate me for doing so.

On my website, and with my clients, I ask for as much notice as possible for a booking.  But at the same time, if they want to suggest something last minute by which I mean 2-3 days notice, I will make myself available for something good.

This approach has worked very well for me.

If you give it a try, you'll figure out through trial and error what works for you. 

I advertise as normal, but haven't been proactive about updating my ads etc., and will probably be losing my AdultWork profile shortly. Regulars know that I have very little availability and need some notice. Newbies I just explain on the phone, or text/email initially. I didn't see the point in writing loads of precise detail because we know blokes don't read it!

I disagree.  Some might not read it, but some will.  Personally, I want the ones who do.  Maybe OP does too.

It's extremely refreshing, and exciting when I receive contact from someone who has very obviously read my website or AW profile. They get straight to the point, details laid out, ready to pay the deposit. Book, confirm as requested, turn up. A delight to have as a client/punter.