First of all, you need to learn the techniques of doing massage in upper back muscles which will help you to massage someone in a perfect manner.
You can practice it on your friend or any family member that feels stress in his upper back muscles. Ask him to rest on the massage table while having back pointing upwards and chest downwards.
Now take a small amount of oil in your hands or in the palm of your hand and rub them together which will make the oil a little warm.
After that, you should lay your hands on the trapezius muscles which are located just below the neck and the starting point of spine adjacent to the back shoulder muscles. Place your fingers firmly on these muscles and rub your hand gently to find tight areas that are stressed up because of workout or exhaustion.
Keep your fingers on the tight areas and put a little pressure to push them down on these muscles. Keep doing that until you feel that the muscles are losing their tightness.
Now you should grasp or hold the tap muscle in your fingers and thumb and then start rubbing it firmly which will help in making these muscles soft.
Make sure you keep your elbows locked in one position and try to use your hands and fingers during massage. It will help you to focus on the upper neck muscles with your fingers which will give your fingers a feel to softening the stressed muscles.
Now you should massage the muscles of upper spine area with your fingers and thumb by moving them up and downward directions. This vertical movement will make these muscles relaxed by releasing the stress.
At the end, you should knead trap muscles with your palm which will help in keeping all muscles relaxed in the upper back portion of the body.