The Slip Knot

Slip knots are used in knitting and crochet to attach your yarn to the needle. Sometimes it's the first step in casting on and crocheting a chain, counting as the first stitch. You can make the Slip Knot just with your fingers.
1. Take a good length of yarn.

2. Make a loop of your yarn as shown.

3. Bring the working end of the yarn through the loop.

4. Catch it up with your needle. Holding both ends of the yarn pull the knot tight on the needle. Now you are ready to "Cast On" and start knitting or make a crochet Chain.