I hit the neck on shoulders day as follows:
- kneel on bench so spine is parallel to ground. Head down and up slowly, 3 x 15 to the left, right, center.
- lay on bench, left side, head off end. Head down and up. 3 x 15
- Same, but right side. 3 x 15
- Flat on back on bench with head off end. 45 lb plate on towel on forehead. Drop head back and then chin to chest. Slowly ... no jerking! 3 x 15
- If no one is looking .... open mouth wide while head is back and stick tongue out 15. Makes all the muscles tense.
Start with 5 reps and work up to 15 over 6 months.
My neck stays at 18 1/2 unless I drop lots of body weight.
No gobbler skin underneath or stringy muscles. Solid all way under.