Write several days ahead if you can, or at least the evening before. In the first message it's best to state the day, the slot and how long you have in mind; also whether the meeting would be at your address or whether you'd rather be given one. Those three details are enough for her to confirm or suggest another option.
Travel is what throws dates out of sync most around here. Ask where the person seeing you is setting off from and add the real arrival time, which in this neighborhood isn't measured in blocks but in minutes on the road. If your timing is tight, say so beforehand: it gets rescheduled without any drama and spares an awkward wait on both sides.
Given the neighborhood's profile, short dates are less frequent than on the west coast. The norm is long meetings, with time to spare, and that's where massage, companionship for a whole afternoon and a relaxed connection with no clock running fit well. Several girls covering the area simply don't take bookings below a certain length.
One last point: be careful about what you share. To book, a name and a time are enough; there's no need to send documents, live location or personal photos, and no serious ad will ask you for them. The same applies on the other side, and that mutual respect for information is part of what makes these meetings work.