Changing Strings on an Acoustic Guitar

To help keep the excess slack in the string from acting erratically while rotating the tuner, use the hand not tuning the guitar to create artificial tension in the string. Gently press the sixth string against the fretboard with your index finger, using the rest of your fingers to lightly pull up on the string. Meanwhile, keep rotating the tuner with the other hand. Mastering this technique will save you a great deal of hassle when changing strings.