Well I AM paranoid a bit LOL and here is my suggestion:
I meet them at my vets office. It is a safe, clean . If they are very young (Florida weather) then I do not allow them to hold the babies. I will hold them at all angles. :-) Also if anyone holds mom or dad and the pups are older I always bring hand sanitizer. No one has ever had a problem with it and fully understands. My mentor that has bred for 25 years lost her 2 prize studs and one puppy because someone came over under the pretense of looking at the babies. Several days later they came back, kicked in the door and stole the dogs. She did file a complaint but it was never "proven". This was the only person she had allowed to come over to see that current litter. Coincidence?? Maybe... but I doubt it. Anyway each breeder has their own comfort levels. Mine is that one... I have had many compliments on how professional I was and all my paperwork is kept in a nice leather briefcase in folder. (I am a paperwork fanatic and neat freak) Deposits are made and copies of the deposits/receipts etc are sent home with the buyer. Then I send them pictures every week of their baby (more often if they chose, but usually they chose once a week). We meet again to give the babies their shots and Florida Health Certs. Works out great. In the meantime I get emails and phone calls and we correspond as much as needed. Hope that helps.. Just another option!
Everyone has their opinions . I have 3 right now out of 6 puppies of my current litter that have deposits and 2 were done the day I took them to get their dews and tails done :-)