The chain stitch is one of the most basic building blocks of crochet. You can use it as a starting or foundation chain and work stitches into it, or chain between stitches as part of a larger stitch pattern.
1. If you're making a chain from scratch (not working it between stitches), you'll need to get the yarn on your hook by first making a slip knot. Slip the knot onto your crochet hook, and pull on the tail to tighten the yarn.
2. Wrap the working yarn (the yarn attached to the ball) over the crochet hook, bringing it behind the hook and up over the top.
3. Turn your hook so that it catches the wrapped yarn, then turn the hook down and pull it through the slip knot that's already on your hook. One chain stitch complete! Repeat steps 2 and 3 until you have the desired number chains.
When you're counting how many chains you've made, don't count the original slip knot or the loop that's on your hook.