Intentionally making nonthreatening eye contact with each puppy in the litter helps them focus on human faces and lays a solid foundation for training and long term relationships. From six to twelve weeks, there should be plenty of variety in the puppies' environments. They can become accustomed to a variety of surfaces, concrete, grass, gravel, linoleum. They can go on short walks and explore new surroundings. They listen to new sounds, such as keys jingling.
Puppies love safe toys, balls, tunnels to romp in.
Ten minutes at a time is long enough, though. They are still babies and tire easily. Conclude whatever you do in a session with pats on the head and lots of praise. It is especially important for them to get used to being handled by men, women and children. They require lots of individual attention, which will take much of your time.