The foundation for all right-hand movements is the ‘basic playing position.’ Place your hand so that the line that your knuckles makes lies nearly parallel to the strings of your guitar, placing your thumb to the left of your fingers.
To play a section using just your thumb, move your forearm slightly forward, your thumb descending on the strings at a steeper angle than in the basic playing position. Keep the arch of your wrist higher, the palm of your hand facing your right shoulder, the line of your knuckles at an angle across the strings. Flex your index and middle fingers slightly, your fingertips lightly touching the golpeador, right under the first string and close to the bridge. Extend your ring and little finger forward to stabilize your hand. Only your thumb will be able to move. Relax your wrist. Now, lift your thumb, then swing it downward, making sure that the entire movement flows only from its joint at your wrist. This is called a thumb stroke. The power generated by the stroke assists your thumb, which falls naturally onto the string. With practice, your thumb stroke will develop great power.
To play ‘apoyando,’ move the tip of your thumb in a line downward and inward – toward the front of your guitar. After hitting the string, continue to move your thumb until its movement is stopped by silent contact with the next higher string. Your thumb should travel toward the middle of your third finger.