I'm making a sweater with two kinds of yarn, with slightly different gauges (almost finished with body, and about to start sleeves). The body is one yarn, and the sleeves and trim will be the other. I'm thinking I'll sew it together and then create one piece that has the bottom ribbing, front placket, and collar band in the second yarn. I would think seed stitch will work for the front plackets, but what stitch would work best for the ribbing (considering it will be worked "sideways") and collar band? How best to turn the corners at the top and bottom of the plackets? Or should I just do it in four pieces (bottom, collar, and plackets)?