This is a heavily modified version of the shrug pattern from here. I used the same type of measurement she suggested, only I made the sleeves waaaaay longer. The ribbing on the sleeves was made with a single crochet back loop only stitch. The pattern on the back is made of alternating rows of front loop only, then back loop only, single crochet.

If I had it to do over, I’d use nicer yarn. The only real problem is that the sleeves make it a little difficult to get out of, and it might be a little too warm for even my frigid wasteland of a cubicle.