Ensure your puppies are on good equipment, it really does make all the difference.
My preferred set up is a standard flat longer lead (about 1.5-2 metres) and well fitted harness. Not only is this often more comfortable for your puppy, it prevents us doing damage to their neck and allows you to be in more control while walking. A longer lead allows your puppy room to mooch and explore the environment without pulling. Puppies walking in shorter puppy leads have very little room for error and need to be extremely close to your leg to not be walking on a tight lead. This can be achieved later on but initially this is too difficult for most puppies leading to a stressful walk for you both.