A slip knot is the first step in most crochet projects. There are multiple ways to create slip knots; this is one possible approach.
These instructions are intended for right-handed crocheters.
How to Hold the Yarn: Grasp the yarn in your left hand, between your thumb and index finger, and allow the yarn to flow freely over your index finger. Support the yarn with your middle finger. Leave a tail of yarn trailing below your thumb.