It is ideal for a purse or a small bag and it is quite easy to make!
If you don't know how to make the ropes, please refer to this tutorial:How to Make Crochet I-Cord Ropes
Worsted weight yarn of two colors of your choice (1/2 skein)
Crochet hook size H
Pinning surface (it could be a pillow, an old cushion, a piece of cardboard, a macrame board)
About your ropes or I-cords: Make them approximately twice as long as you would need them. (I suggest you leave one end of the I-cord or rope attached to the ball of yarn just in case you need more to get your desired length. This thing is definitely not a precise science!)
Pin the cord to your pinning surface, leaving free the end that has the ball attached to it. If you can manage your knotting with the ball, that is just wonderful. You can also wind some extra yarn to a wooden clothespin to make sure you have some extra yarn to work with in case you need a bit more I-cord, and then work, using the clothespin as they used to do macrame a century ago by using bobbin lace bobbins (you can use modern bobbin lace bobbins too), do whatever you consider, but it is best to have some yarn left than to be short on cord and no yarn to work with and to have to start all over again!
To make the strap proceed as follows:
Make 2 I-cord or crocheted ropes of each chosen color.
1- Leaving the rope on the left hanging and holding it straight with one hand, bring the one on the right to the front and around it towards the back, forming a rounded loop, then pass the end of the rope through to the front again. Tighten.
2- Now keeping the right rope hanging and holding it straight, repeat the process by bringing the one on the left to the front of the one on the right and around it, forming a rounded loop, and then pass the end of it through to the front. Tighten.
Repeat these 2 steps to form your pretty strap.
That was easy, wan't it?