I am making Matilda some undies using the that darn Kat pattern. If you remember I made George a whole heap of boy ones and bloog about them a couple of weeks ago. By the time I got to Matilda's I was pretty over them, but in particular the fiddly part where you have to add the ribbing to the leg and waist holes. I decided to cheat a bit with one pair, to see if it would save time, by adding the ribbing first then sewing up the side seams. Its a bit quicker to work with ribbing on the flat, but the down side is that you dont get that nice smooth cisrular band- plus you end up having to cut and add 4 bits of ribbing. A good compromise might be to add the leg bands on the flat, then sew up the undies and add the waist band as a circular piece. The Undies are still just as robust when worn and washed, so this might be a good option if you are planning on sewing up a big batch of undies.