Most acoustic guitars have one strap button (also called an "end pin") on the back end of the guitar. While some manufactures install a second strap button under the neck heel for strap attachment, others do not. For these guitars, putting a guitar strap on the guitar can be accomplished one of two ways. A second strap button can be installed by a qualified repair shop, or the traditional method of tying the strap to the headstock can be used. Tying the strap to the headstock does not modify or harm the guitar in any way, and it takes only a few minutes.
Fold the shoelace or leather cord in half, and insert the looped end into one hole in the guitar strap until it sticks out about one inch. If your guitar strap was supplied with a lace or cord already attached, skip to step 3.
Take the two loose ends of the lace or cord and place them through the loop sticking out of the strap hole. Pull on the loose ends to tighten the knot.
Insert one of the loose ends under the guitar strings just above the string nut, until it sticks out several inches. The nut is the small rectangular piece at the end of the guitar neck, which suspends the strings from the tuning key over the fretboard.
Place the other loose end around the back of the headstock behind the nut, and tie the ends together. Tie a doubled non-slip knot, although the type of knot is optional.
Trim the excess lace or cord with scissors.
You may use any kind of strong cord or thin rope as long as it is soft (to prevent possible guitar finish damage) and pliable enough to hold a knot. Keep the lace or cord out of the way of the tuning keys to avoid contact and accidental turning.
Installing a second strap button on your guitar can cause serious guitar damage if improperly done. Always entrust repairs that require body drilling or modification to a repair shop. Periodically check the knot for tightness to avoid strap disconnection and consequent guitar damage if it should fall.