I think the ladies have covered most points but if you are curious, there is a post on UK Punting that I came across which details what guys believe to be a successful escort meeting. Take it with a pinch of salt though, you know what those guys can be like!
For me -
Communication - Answer calls / emails / texts as soon as possible. Even if you miss a call, message them and say thank you for the call and detail a time they can call back. You might have missed a spur of the moment booking, but they will remember your consideration and try again in the future. Always send confirmation message the morning of the booking. You may have 5 bookings that day, but they are likely only seeing one escort, make them feel special. Plus if they don't get back to you, then you can fill the booking time asap.
Be grateful - Always thank new clients for getting in touch in the first place "thank you for contacting me, thank you for your interest in me, thank you for your message / call". Always thank clients for visiting you when they depart too. Leave AW feedback.
Ensure you know exactly what they are looking for - and if you offer it, then provide it to the highest standard!
Remember details! - If they have told you something about themselves, their likes, etc, them remember it! I always try and remember one detail about a client so that when they visit next time, I can slip it into conversation so they know that I have previously been paying attention and don't just churn them out. I remember client music and clothing tastes and put something appropriate on for their booking.
Offer to hang jackets / coats and put back on for client when they are leaving.
Offer drinks.
Provide toiletries and fresh towels.
But most importantly - BE YOURSELF - as fakeness is spotted a mile away and is not appreciated.
The key to my service is making the client feel that he is the only client I am seeing that day and that my time and attention is absolutely devoted to him during our time - it works for me. I am almost always booked for every hour that I am working and have bookings placed as far as a month in advance!
Hope this helps.