So my coat for this winter, although beautiful, does not have sleeves. Which makes for some really unhappy arms in snowy weather. It's also a pain to have to wear long-sleeve shirts all the time just to cater to my coat, SO to remedy this, I made my own pair of arm warmers out of an old long-sleeve shirt that I no longer wear.

What you'll need to make your own:
-Long sleeved shirt
-Sisscors
-Needle and thread
-Pins
-Sewing machine/serger (I used both in this project)

Step 1: Cut Off Sleeves

Take your long sleeve shirt and cut the sleeves off.
I cut mine off as close to the seam as I could because I wanted them to be as long as possible, but you can really make them any length you like.

Step 2: Fit Them to Your Arm

All you're doing here is fitting the sleeve to your arm better. The shirt I used was too big for me so the arms were really loose. If the shirt you use fits better in the arms then you can just skip this step.

Turn the sleeve inside out and put it on your arm. On mine, I wanted them to hang down to about my knuckles so I fit them with that in consideration.
Using the original seam as a guide, pin the sleeve so it fits snugly on your arm. (It was sort of hard to do this one-handed so you may want to have a friend help with this)
I then serged along where I pinned.

Step 3: Make a Thumb Hole and Finish the Edge

Decide where you want your arm to poke through and cut a very small hole in that spot. Remember that it'll stretch a little and you can always make it a little bigger. Just don't go hog wild with your first cut :)

Once that's done, using your needle and thread stitch all the way around the opening of the hole. This will discourage fraying and too much stretching.

Then just finish the edge at the top of the sleeve and you're done! To do that, I just folded it under about a quarter of an inch and sewed all the way around.

I think I'm also gonna make a pair of these out of an old sweater for some added warmth :)
Enjoy!