The slip knot represents the first loop on your hook at the beginning of a project. The intention is to create a knot that allows the loop to slide so that it can be adjusted to be not too loose and not too tight.
After looking around for a good video that clearly demonstrates an easy way to make the slip knot, I decided to make my own! One of my students showed me a way to make it that is so easy and understandable. Here's my new YouTube video demonstrating the technique:
Hope this helps you get your crochet projects started even better and faster!