Ask any visitor that comes to visit to handle the puppy around; touching the paws and feeling among the toes; using the ears; offering restrained hugs; playing with the mouth and starting the mouth putting your finger on the puppy's tongue. If at all possible expose your pup to children and train them how to handle the doggie properly. Always make sure when children and pet dogs are playing mutually they are supervised. You don't want the children to experience too about with the doggie and you don't want the puppy getting so hyped up by antics of children and becomes out of control.
A lot of puppy socialization may appear in the house environment - exposure to loud banging sounds, such as clanging pots and pans, vacuum cleaners, washing machines, yard mowers, etc.