STANDARD KNOT
The standard knot can be used for closure of necklaces as well as for bracelets. It is a most secure way to fasten the ends of the string or lariat, because the knot never comes undone.
#1. Fold the bracelet together and slide charms onto the center of both sides of the bracelet.
#2. Take the ends of the bracelet and loop them through the folded center.
#3. Fold the ends back to create a loop.
#4. Draw the ends through the loop and pull to tighten.
STANDARD KNOT VARIATION
Try placing your charms in two layers before you fold the string and tie the knot, or secure the knot even more with a decorative clip charm.
#1. Fold the bracelet together and slide charms onto the center of both sides of the bracelet.
#2. Take the ends of the bracelet and loop them through the folded center.
#3. Fold the ends back to create a loop.
#4. Draw the ends through the loop and pull to tighten.
#5. Affix a PANDORA clasp just to the side of the loop in step #2.

Take a look for inspiration: