Pretty girls, especially facially pretty girls can be hard to book. Here are a few tips that have worked for me in the past.
-don't bother texting during times they aren't known to be working, when they decide to work they want to get the bookings arranged with the fewest hassles and thus won't bother responding to old texts as the guy may not be available anymore
-do text during times you've observed her to be working, indicate the time time range you are available
-if can receive texts hours after you send them then indicate so, if you can't - indicate that as well
-be polite, indicate you hope they are well, give a name
-state how long your looking to book
-don't ask any questions regarding services, location or rates on first text - establish mutual availability first
-even if she does answer, she's probably got lots of other potential guys, the fewer questions you ask the more likely she'll see you
-be patient, they may give an initial response, see a guy and then get back to you 40 minutes later
All a lady wants is a guy who'll show up on time, pay and be respectful and not push for services they aren't comfortable giving (especially on the first encounter). They get a pretty good feel for whether you're that kind by the tone of your texts and the questions you ask.
Something like this....
Hi xxxxx, my name is xxxxx. I hope you are well. Are you available for 30 minutes sometime between 7:00 and 11:00pm? You can text me back anytime up until 9:00.
You may get something back like 'Hey hunnie, rate is 140hh, 200hr'
Don't be discouraged, think of it is a nibble on a fishing line