You can use any size starghan. The one on the left is somewhere in the 36" range, and the one on the right is about half of that. (And you'll just have to ignore all those loose ends that I haven't woven in on that blue one, k? thanks!!)
Lay your blanket out flat in front of you. I found it a little easier to start with two points towards me, like the pic on the left.
Fold up the bottom two points so that the are level with the tops of the "arms".
There's a little pocket formed when you bring the bottom up. Tuck the folded over point of the star in here, and your finished product looks like this:
SOO easy once you get the hang of it! You'll be thinking you're Martha with your fancy blanket-folding skillz!!!!
Let me know if you try this, and if it works for you. I'd love to know :)