IMO it's much better than the chain method, I use it wherever I can no matter what the pattern says. Some instructions are overly complicated and make it seem harder than it is. I'll have a go at writing them but if you can find the right video it'll be a lot less confusing.
Basically, lay the yarn over your palm with the tail pointing to you then loop the yarn around in a circle on top of that so that the ball is at the other side of the hand. Take your hook, put it through the centre of the loop and yo (it can be tricky to hold everything tight enough here when you're starting out), pull it through to the centre of the loop, yo outside the loop and pull through loop on hook. Now the slip knot is made and you have a ring that you can crochet in to. After you've done the required number of stitches, just pull the tail and it will close up tight.