My own, obviously!
Friendly, chatty, caring, professional and thorough.
Most of my customers come back and book with me again, often many times, and I've become their personal travel agent.
Paperwork....especially passports. Make sure they're in date by at least six months after your return dates. Make sure the name you booked travel with is the same as your passport (!) and check to see if you need a visa to travel somewhere. If you're getting married abroad, make sure you've check up on any local requirements.
I ask lots of questions in order to find out exactly what sort of honeymoon customers want. This can result in lots of messages passing between us until we get it right for them.