I have a pair of legwarmers I wear a lot. I can tell how they are made and have been thinking of making another pair or two myself. You would have to take your own gauge and also leg measurements and calculate the number of stitches. But, here is how I would do it:
Using 4 circular needles - a double set of a smallersize, like say size 5 if you were using worsted weight, and a double set of a size about 3 or so sizes bigger, like about size 8 for worsted weight acrylic yarn. The entire thing is done in K1P1 ribbing, worked in the round. But the bottoms and tops are done using the smaller needles to make the ribbing more snug. If you had circulars that were small enough in length you might be able to get away with just using one of each size, 5 and 8. You could also use DPN's but I find them very difficult and lose patience! I have a ton of circulars so why not use them I guess! Or you could even get away with working them flat and then seaming them up the back. I have found 2 circulars works great when working a small piece in the round.
Let us know how it turns out!