The SAAFE main site has a lot of excellent info on security. Everyone does this a bit differently. For private residences I always have a security buddy who knows where I am and what time to expect a call to say I've finished and I get the client to pay up front for an uber or addison lee cab to take me from my place to theirs. They have to book the cab using their credit card or paypal in advance so it works like a deposit to deter timewasters and having to use their card with their real name would put off anyone who's up to no good. For hotels, ask for their name and room number and call reception and ask to speak to Mr X in room Y so you know they're really checked in where they say they are.

I go with my gut and if I ever have doubts, I take extra measures. If anyone asks me to travel far, I ask for a deposit, that tends to weed out the TWs. Ensure you take client details prior to the meet and use your intuition. So far, I've never had no shows etc and I only do outcall.

As mentioned everyone does the security differently. For me I firstly go by my gut feeling- if they seem a little off or weird then I'm not going, full stop. I've ignored my gut feeling 3 times- and regretted it 3 times!
Secondly; if they turn out to be a Timewaster and I have to make the journey back, will it be a big financial loss to me? So if you're relying on taxis or a driver etc and its a long journey will it hit your wallet hard if they're a messer? If its a yes I ask them for a deposit paid upfront via bank transfer. I've never had a client pay a deposit and turn out to be a Timewaster.
And finally- I always, ALWAYS have a friend who knos where I am and what time I finish. If I don't check in with them when I finish then they know somethings wrong.

Stay safe, and remember to follow your gut feeling- its usually right!

I use the electoral role for homes "find free people" & ask to be put through to Mr what's his name in room xyz for hotels

I dont do outcalls because it hasnt given me anything but tws. Wheni did finally screen them right I was told my process was too extensive 

Never let the client tell you your screening process is too extensive.

The above info is all great, as the other ladies have said, check the main site. Always checking the landline number is non negotiable for me. You should set yourself limits with what makes you feel safe, and never let yourself slip. For example, if I can't reverse lookup an address, I don't do the outcall. Simple as. Even if the client seems ok.
When I first started I only ever used to do outcalls to someone's home if I had met the client previously at a hotel, but I have more measures in place now to let me do it.

I think this advice-only go to people's houses after meeting them at a hotel first time-is good advice. I went for first outcall at someone's house the other night and I had never met them and it was a surreal, uncomfortable experience and all I could think was, what if another man (or men) suddenly appear. Very vulnerable position to be in. Have never felt like that in a hotel.