There are many, many methods and reasons for using counting strings. The three advantages of this special crochet method are:
1 the threads are held perfectly securely
2 the resulting necklace of bundles can be stretched for ease in counting, and
3 it’s easy to undo the chain when you no longer need it. Take the tails back through the last loop and pull on the tails.
At the beginning:
Take a long string (about 3 feet), fold it in half and slip the two tails through the loop at the fold around your group of threads. This makes a lark’s head knot over the group.
With the tails of the lark’s head you will begin to crochet around the bundles as you make them.
Looking at the first illustration, measure out your next groups of threads. Fold the tails between the first bundle and the new one, making a loop. Then put your right thumb and forefinger into the loop, while holding the tails with your left hand.
Encircle the new bundle with a “crochet” by using your finger and thumb to draw up another loop from the tails. Holding onto the tails, pull on the loop to snug it up around the bundle. Leave that loop and the tails dangling (don’t pull the tails through the loop, as you’ ll be tempted to do).
The larks’ head is the foundation. From now on, you’ll crochet-chain using your fingers like this. Measure the next group of threads. With the thumb and forefinger, reach through the old loop, drawing up a new one from the dangling tails, and tighten to secure the new bundle.
After each crochet, both the loop and the tails should hang freely, ready for the next bundle.
To end the counting string chain, at the last bundle, pull the tails completely through the loop so that only the tails are hanging freely.
To undo the chain FAST, take the tails back through the last loop and pull on them (the tails).