Start by measuring your wrist to decide how big you want to make your bracelet. Then cut off the piece of rope you need.
Tie the yarn to one end of the rope.
Then start wrapping the yarn around the rope.
Continiue twisting the yarn 'til there are a couple of centimetres left of the rope. Put some glue on the top and wrap the rest of it.
Now the end should look something like this.
While the glue is drying for a moment you can make this little braid which will function as a piece of the "lock". I usually make mine about 3-4 centimetres.
Then add some glue to the other end and place the braid in a loop on it. Then twist yarn around the top.
Sew a button to the opposit end and...
Voila, done :)