What are some safety practices and/or tips for first time Meet and Greets?

I usually greet the clients outside in the front yard where it's more of a neutral meeting place, that's where I introduce myself to the client and dog. The. I will have my dogs go outside to meet them or I will do a one on one with each dog to get them acclimated and see if they get along. This is usually done through a glass door so they can see each other first. If they seem to want to meet then I will take off the leashes (indoors) but keep on harnesses in case I have to grab anyone. Also have a spray bottle with water on hand in case a fight breaks out. It's an easy and humane way to catch them in the act and show them it's a no-no

I haven't had any problems with clients coming to my home or going to a client's home. I live alone and don't have dogs, so I just let in the dog and parents and let the dog roam around the house while I supervise and show the parents where the dog will be staying. Areas where the dog(s) are allowed are my living room, dining room, kitchen (where they are fed), and my bedroom. The other rooms are off limits, except for my office where they are allowed when I'm in there. And of course the back yard.

I always have my cell phone handy in case something happens. But if I don't feel comfortable with a client in my home, I would just tell them politely that I have another appointment and I have to leave. If I'm at their home, I would say the same thing.