You want to use the big parts of the hand—the palm and the heel. You can use even your elbow. For instance, if you're standing behind someone sitting in a chair, put your elbow on the shoulder muscle, where there is always a lot of tension. Lean gently, very slowly, applying pressure for three or four breaths. Then move your elbow an inch or two away and put pressure in the next area.
The key to a really good massage is long, slow, deep. Just think 'LSD.' And feedback is very important: Ask your partner, 'How is the pressure, on a scale from one to ten? How deep am I now?' You want a seven or an eight. Most important is: 'Does this feel good?' Ask again and again, and adjust your technique accordingly."