Before I ever try and lead them, my calves get a rope halter on and drag it. They quickly learn that if they step on it, they have to stop and reposition their feet to free their head. They learn to give to the rope. Sometimes if mom is laying on it, they will just stand there like they are tied. It may sound mean, but their face gets a bit sore. Then when you pick up that rope, they will follow you anywhere. They won't drag you either.
Side note, I use a rope halter with a ring in it, so it loosens when there is no pressure.
