I never use force or coercion when teaching puppies to walk on a leash. I prefer to use a retractible lead. I avoid every giving a puppy any tension to pull or buck against. I use food and praise to coax a puppy along. Once they learn to follow, I will gradually and gently apply gentle pressure to the lead to encourage them to learn to move forward towards the pressure. Patience and kindess is key in teaching puppies to learn to follow and come along.