Here I am at the end of my final row and ready to fasten off.
I cut the yarn, separating the leftover yarn from my work, making sure to leave a six to eight inch tail.
I make a chain stitch, just as if I were starting a new row.
However, instead of turning and crocheting I remove the hook and continue to pull up on the yarn loop created by the chain stitch. I pull until the tail comes all of the way through.
Finally, I pull tightly on the tail to create a tight nub. Now I'm ready to weave in my end.
That's all there is to it! Now that you know how to fasten off you can rest easy and trust that your crochet will not unravel.