Use craft or butcher paper or if unavailable newspaper will work fine. Trace around the leg, keep foot flexed down to create as staight a front line as possible. You will use this to be your fold line for the pattern.
Step 2: Draft straight line for fold.
Use highest point and approximately where the end will be, draw straight line. Fold paper down this line.
Step 3: Square top of pattern.
Draw a line perpendicular to the fold across the top of the design line. I added 5 inches in height which I sqaured. I did this so my leg warmers would have more scrunch. The amount you add or not depends on your own choice.
Step 4: Add 3" for girth and seam allowance
I started with 3" knowing I would be using a 1/2" seam allowance. The blue furry pair worked well with this measurement, they were easy to get on and a bit loose over my boots. For the black low nap fur pair I only added 2 1/2 ", again knowing I would use a 1/2" seam. The black fur I had a bit of stretch (the blue fur did not stretch at all) and I wanted them a little tighter so the scrunchy folds would hold better. It is better to cut them a little too big and then stitch in a second time if they come out too big. If you cut them too narrow the first time, you will have to start all over.