I worked out my neck for the first time by laying on the end of my bed with my head hanging off, and bringing it up and down till failure.

I'm not sure how people naturally got strong necks (probably due to natural posture from walking all day like we are supposed to), but working it out specifically put my head into the perfect natural chin tuck without any pain (before it hurt my neck to put my head into a chin tuck, and I felt all stiff). I don't even have to focus on it to do it. Its literally my natural head posture now. My neck also instantly had previous pain relieved and I feel like I can move my head all around. Most male models, if not all, have above average neck thickness which I think helps them also to put their head in a natural chin tuck.