1. Cut a piece of yarn about 1 foot long. I used Knit Picks Hawthorne in Compass, which is a Fingering weight yarn. I thought the thinner yarn made the star easier to see.
2. Start from the inside of the hat, and follow the order of the numbers in the diagram. Go up at the #1 spot, then down at #2, and so forth. Make the star bigger than you think would look good, because it will pull tighter through the stitches and "shrink."
Up through #1, down through #2.
And, finish off going down through #8.
3. When you are all done, the star will still look pretty messy. This is inevitable, as you should go in and out of knit stitches, and so it may not be exactly even. To finish it off, go up through the hat at the center of the star, across the star, and back down the same hole into the hat. Do this once across horizontally, and once up and down vertically. Once back in the inside of the hat, weave the tails in on the wrong side.