Another popular necklace is the “Slide Knot” Necklace
The idea is to make a knot, on each side of the necklace, in a way that it will allow the cord to slide through the knots so you can adjust the length of the necklace.
Here is how to do it:
Cut one piece of string about one yard long
Hold the circle at the middle of the overlapping part and with the end part facing to the right make two or three loops around the part it overlaps, from right to left.
Next insert the end of the cord through the loops from left to right and pull holding the other side until you have a knot like in the picture.
Some people put a drop of clear glue on the knot to prevent it from becoming loose. If you do that make sure the glue stays on the loop and it doesn’t go on the sliding cord.