I always get a lot of comments asking about the thrumming process so here goes:
Before you can add your thrums to your knitting you have to make them. It starts with pulling out pencil sized lengths from whatever fiber you're using.
Then you wrap those skinny bits around your hand and roll them together using your other hand making a loop. You take the loop you just made, lay it down and with the side of you hand roll the middle until you get a bow.
You pull the middle of that bow through the stitch below the one you want the thrum in and then knit it together with that stitch. That locks it in place. I have never had one come loose. Not even went they went through the washer and dryer....ahem.
When you finish that round you get something that looks like a troll doll. Remember those? I still have one.
Then you tuck in all that wild hair and knit three rows plain. You repeat all this fun until you get to the top. The thumb is an afterthought and follows the same thrum pattern. When you're all done you have a soft cloud of a mitten that is so warm and so cozy you wonder why anyone ever bothers making any other kind.