Every crochet and knitting project begins with one thing. A slip knot.
This is how I make my slip knots, which are 'backwards' compared to other slip knots I've seen. Though really, mine is better, so all the other slipknots are backwards. Anyways, if you are crocheting in the round this slipknot allows you to pull that hole in the middle tight.
Start off pointing a gun with your left hand. Pew! Pew! Hold the yarn tail with your pinky and ring finger. Ignore my nails.
Take the leading yarn end with your right hand and bring it to the front.
Cross the leading yarn over your left hand to the crook of your thumb.
Pin the leading yarn down with your thumb and pick up the yarn tail.
Bring the tail yarn in between your first and middle fingers.
This is the slightly tricky part. You're going to pull the tail yarn up through the loop around your first two fingers without letting the actual tail of the yarn slip through. It's easiest to do this by pinching the tail yarn with your first and middle fingers of your left hand and bringing those two fingers up while pushing the loop from the third picture down with the first finger on your right hand. It's like loop-ception. A loop within a loop.
Place the loop on the first finger of your right hand. Pinch the leading yarn with your left hand and the tail with your right, then pull both ends until the knot is tight.
Slip the loop onto your hook or needle and pull it to the right size with the tail.
So that's it! It may take a couple of tries before you get it right, but don't despair! I once had that problem too, but I rose above it to be the crochet master that I am today. Maybe, one day, you can all be like me.