Being a hand-knitter as well, one of my favorites to knit are what I call "ankle warmers" or just short leg warmers for fall and winter. My winter footwear is either a pair of knee-high boots or my trusty Danskos and I like to rock the ankle warmers with tights or leggings and my Danskos. For those not knitty-inclined (or those pressed for time), you can easily grab some knit yardage and fashion up an easy pair in no time. I even found this grey rib knit in the sale bin!
Knit yardage is formed the same as knitting with needles, as far as stitch formation. Knit stitches (as opposed to purl stitches) are considered "right side" and a rib knit is variations on alternating knit and purl stitches. The rib knit I picked up is a Knit 2, Purl 2. Knit has a specific direction and in general for knit garments you want the greatest amount of stretch to be around the body.
You're welcome to play around with proportion but what I landed on was 10" x 19". Fold in half length-wise (so my piece looked like 5" x 19" with a fold on the right or left side) and seam with a 1/4" seam allowance. Choose a stretch stitch on your machine (even a simple zig zag stitch will do) or bust out the serger.
My finished leg warmers are longer than my ankle warmers, something I wanted. You could easily make them shorter (or longer!), and narrower. Knit doesn't fray like wovens, so I simply left the top and bottom edges raw. Perfect for a rainy day.