Big TW giveaway for me is - Are you working today? Then they don't give a specific time 
Yes! Or I'm outcall only, and they go, are you working? OK I'll send you my postcode. I always say where are you roughly, then they start with how much is it, what services do you do?
OK so....you were about to send me your postcode to come and see you, but you don't know if it's ?100 or ?100,000, and you don't know if you're going to get sex or a request to take me to dinner? Riiiggghhht.....