The two principal ways of playing single strings with the right-hand fingers or thumb are called apoyando (the rest stroke) and tirando (the free stroke). To perform apoyando, rest your striking finger against the next (upper) string as you complete the stroke. For tirando, keep the line at which you strike the strings parallel to the soundboard of the guitar, rather than down toward the soundboard as in apoyando. The striking finger or thumb does not touch an adjacent string.
Move your whole finger from its joint at your knuckle. Move the tip of your finger in a line pointing toward the ball of your thumb. Do not hook your finger into the palm of your hand. Bend the middle joint of your finger in a close approximation of a right angle as you begin your stroke. Your middle finger will bend slightly more at this joint as you strike. Swing your whole finger from the knuckle joint to give your stroke more power. If you practice slowly, you will start to feel the correct position as you move your fingers, continuing their movement after striking the string, until your fingertip rests against the ball of your thumb. Normally, your finger will not move this far. This exercise exaggerates the motion from the knuckle joints, in order to increase your fingers’ strength, especially in the weakest finger, the third. At the moment when you strike the strings, the tip joint of your striking finger will actually bend slightly backwards if your finger is completely relaxed. This is important, since you are trying to get your finger to move from the knuckle. The degree of tension in each stroke varies according to the style of the music, and that of the guitarist.
When you play arpeggios, move each finger independently of the others. When you play chords, move your striking fingers together from your knuckle with the same movement that you used for your single finger. Move only your fingers, keeping the rest of your hand, and your wrist, relaxed, unmoving.
To achieve the optimum position, keep your thumb aligned with the strings. The impact should be more on the side of the tip of your thumb, both on the nail and on the flesh. When you play tirando with your thumb, you should move similarly, except that when you follow through, clear the next highest string, rather than resting against it as you would in apoyando. Move the tip in a circular or oval path at right angles to the plane of the strings, with your thumb moving entirely from its joint at the wrist without bending at either of the other two joints, keeping your knuckles parallel to the strings.
Flamenco music rarely employs thumb tirando. When you do move your thumb, however, keep it independent from your fingers’ movements. Cultivating this independence is crucial to achieve good right-hand technique. The weight alone of your relaxed hand will be enough to maintain control.
Beginners often have a tendency to straighten their wrist. This error brings their hand too close, causing their knuckles to be at an angle from the strings. Take heed, therefore, to make sure that your hand angles downward and away from your body. Keep the arch of your wrist relatively flat, meaning that the flat part of the back of your hand lies nearly parallel to the front surface of your guitar. If the arch is too high, it limits the power that your fingers can exert. Bring the right-hand side of your palm down, close to the front of your guitar, no further from it than from the left side (as seen when your hand is in the proper position for playing). This is a defining feature of the Flamenco right-hand position, since it strengthens third finger, giving it more power as it strikes the strings. Use the positioning of the knuckles in relation to the strings as a useful reference point in studying the details of right-hand technique. As you advance in your studies, you will be able to explore how you can alter these details to fit the anatomy of your own hand.