1. Yarn over (wrap the yarn around your hook from back to front).
2. Insert the hook into the third chain from the hook (or the stitch you want to work into).
3. Yarn over again and draw the yarn through the chain (or stitch).
4. You should now have three loops on your hook.
5. Yarn over again and draw the yarn through all three loops.
6. Now you should have one loop on the hook.