There are 6 ways to use the foot for Sokuatsu massage:

Big area - Big Area is the entire sole of the foot. Try to apply pressure with evenly distributed weight. You can massage without damaging the muscle fibers and capillaries.
Small area - Small area is the area between the toes and ball of foot. This is used by a bone and very tight spot.
Long line - Long line is on the side of the foot between the pinky toe and the heel. This is used for the muscles big and small. It is also used to improve the circulation and lymph flow.
Short line - Short line is the line across the tip of the toes from the big toe to pinky toe. You bend all your toes to massage with this part. It is used to press more specific area with firmer pressure than the long line.
Big point - Big point is the ball of foot that shows when you lift your toes. It is used to press even more specific area with more pressure than short line.
Small point - Small point is the tip of big toe. It is used to firmly press.

Practice the use of these 6 parts on yourself using the other foot.

5. 6 Ways to Use Your Foot