step one: one red sweater, one white sweater. both 100% cotton (not important) cable knit (for stretch and slouch), a bit of white yarn, some red/white thread (colors don't really matter), straight pins and sharp sewing scissors. Also, a sewing machine and sewing needle.
step three: cut the bottom band off of both of the sweaters. You won't need them for this project. Then, cut a few strips of whatever width you feel like from both shirts (through both layers). I cut 2 from each shirt.
step four: line the cuff of your hat up with one of the red stripes. cut the red stripe about an inch or more bigger on each side (using both the front and back of the sweater). Sew this stripe, right sides together, on the short side like you did the cuff. Pin the white piece to the red piece all the way around and sew. Make sure you are pinning right sides together.
step five: lay out your stripes and cut each one to the desired length (again, cut through both layers, but use the fold). I used each strip of sweater twice. In the picture, you will see my first stripe sewn to the cuff of the hat, and each stripe laid out and cut to the size I thought would work. I was relying on the fact that I had more of my sweaters left in case I messed it all up. You can also see that the stripes aren't all exactly the same width, but it didn't matter. The finished product looks great.
step seven: I turned the hat inside out and sewed the top closed. I really can't explain to you how I did this. I kind of bunched the top hole into an X shape and sewed into the middle, then sewed the point of each X to the point across from it, if that makes any sense. Basically, just gather it up and sew it back through several different ways. I turned it right side out and it's done except for the last step!
step eight: use the white yarn (i used a long scrap) to make a large pom pom. I wrap the yarn around the 4 fingers of my left hand (loosely), then take a shorter piece of yarn and tie around the wrapped yarn in between my middle and ring fingers. Tie it tightly so it doesn't come apart when you cut it. Take it off of your fingers and cut the ends so it makes a nice fluffy pom pom. Now sew this to the top of your hat. I also frayed each piece of yarn in my pom pom to make it even fluffier.
...and it's done! Here is my daughter modeling her hat. Now, an hour after it's done and I'm taking forever to write this tutorial, she is still wearing her hat and asked if she can sleep in it.