OK first just get a pair of socks...stretchy ones are best..i like fuzzy too. Even better if you can get ones with a design on them :)
sorry i didn't take pic at the cut off stages...but it is really easy...just cut a few inches off where your toes would have gone...try them on to see if this is a lengh you like ..(tip..to help measure just remember thumb hole is gonna be where the heel is) Now cut a little slice in the heel area,,i would say about 1/2 inch to start off with. Then cross cut in that same slit (remember - very little cuts...it is easier to go bigger but you cant make the hole smaller once you have done a cut.) Then it is time to do a tight whip stitch around the thumb hole. I use a embroidery thread and place my stitches as close as possible. I do the same for the bottom raw edge..it gives it a wavy look which i really like :)
Tada.. my daughter's hands are much prettier than mine but she was unavailable this time so these are my chubby hands. They are warm and comfy :)
Another tip is to insert a round object ..like i did with this medicine bottle and stitch around it. Makes it easier and give it a uniform look on both sides. Play around with different size bottles and find which one fits you best. I have even seen other tutorials use their thumb...but i am too afraid of poking myself
this is a fun project and you can really embellish the arm warmer after. Have fun and let me know how yours come out :)