What you are going to do is activate the muscles used to create a motion but not actually move the body part. In the neck we are going to work on - 6 key ranges of motion:, flexion, extension, right and left rotation, right and left lateral flexion. Isometrics can be done seated, standing, lying down, using your hand, a pillow, the wall, or an assistant to block the motion. The Isometric should be done first from a neutral head position, but then you can advance towards doing the isometric activation at the end range of motion also.
End Range Isometrics can also turn into Neck stretches, and you can gently use your hand on your head to guide you into a deeper stretch
Use it or lose: use this concept is all your movement. For Neck Range of Motion the mnemonic is - YES/NO/Maybe, and paint a rainbow with your nose - Use it or lose. This is range of motion exercise for the neck. You should do about 5-10 repetitions in each direction.
Flexion/Extension isn Yes, Rotation is No, and Lateral Flexion or side bending is Maybe...Tucking the chin down to the chest as far as it will go is flexion, looking up towards the ceiling bringing the head back as far as it will go is extension, turning your head as far as it will go and looking with the eyes to the left and then to right is rotation, then tilting the head like bringing your ear to touch your shoulder on the left and then on right is lateral flexion. Then paint a rainbow with your nose, start by bringing your head into flexion, chin to chest, then turn the head like your bringing your chin to one shoulder or like you are going to try to smell your armpit, then you are going to do a rotation a full circle with the head, but we are going to protect the back of the neck from compression by keeping the neck long, so imagine the is a rainbow going from one shoulder to the other and you are going to trace it with your nose from one shoulder to the other and then back again.
Laying on the ground laying on a rolled up towel or a cervical pillow. Roll up a hair towel very tight and long enough to go from shoulder to shoulder, about the diameter of a baseball or a small orange. Then laying on your back, placing the roll under your neck. The roll should be pressed tight to your shoulders, and the back of your head and the back of your shoulder blades should comfortably touch the ground. Your knees can be straight or bent and should be relaxed. Lay on the roll 10-20min daily.