Steps you need to follow for doing Chin Tuck:-
This can be done standing or sitting
Sit upright, keeping your ears over your shoulders and then place a finger on your chin
Without moving your finger, slowly pull your chin and head straight back until you feel a good stretch is felt at the base of your head and top of your neck.
Your finger and chin should now be separated with your finger acting as a point of reference for you
Hold this position for about 5 seconds and then return your chin to your finger
Repeat a total of 10 times about 5-7 times a day