One FFL I previously used had a good policy about that. They insisted that the shipper put the name of the customer on the outside of the package. Without a name visible, they'd refuse delivery.The reason they gave was that if a customer decides they don't want it the gun shop gets caught in the middle, blamed for scratches, etc.
Immediately upon delivery, they'd contact the customer and make an appointment. When the customer arrived, they'd open the box in front of the customer. The customer got to see exactly what came in the box and exactly what condition it was in when it arrived. The FFL doing the transfer could never be blamed for condition issues or anything like that.
I always thought that was smart. Then they decided that transfers were too much trouble, upped their price to $75 per, and got out of that business.