1. I always, always talk to them on the phone to literally sound them out.
2. Once a booking time has been agreed I ask them to text to confirm one hour beforehand.
3. If I don't hear from them I'll either ignore if I had any TW vibes, or text them at about T-45 minutes from the booking time, asking if they still want to meet; I'd say about 70 percent of the time I don't hear back, 30 percent they've forgotten or got held up at work etc.

When they want to come over I dont give them my full post code I only give them the general area.
I ask them to call me when they are leaving once they are in their car I give them my full post code so they can enter it directly into their sat nav whilst I'm on the phone.
I then ask them what road does it bring up and how long does it say it will take to get to me.
That way I know they have really put it in and put it in correctly and I have an idea on how long they will take to get to me.
I've found genuine punters don't mind jumping through a few hoops as they understand we need to weed out TW's