What to look for from a trainer

Hello, I've been a member of a gym for a year and would like to meet with a trainer to discuss a plan that would give me the greatest benefit in the limited amount of time that I have to work out every evening.  And discuss nutrition.  I've been observing the trainers for a couple of months to see who had a steady stream of clients and repeat clients.  My thinking is if the person is good they will typically attract new clients by word of mouth and retain old ones.  I've never met with a trainer and would like to know if anyone has any thoughts on what I might look for and/or expect from a trainer.  Thank you.

Phyllis