I've wanted to make a vertically striped sweater for a while now. I'd been saving some sportweight grey, brown and copper alpaca yarn. Then a discussion on the Tunisian Crochet list described a honeycomb stitch pattern of alternating Tunisian knit stitch/Tunisian perl stitch as a way to get a lightweight, drapey fabric, and everything came together.
The point of modular clothing design is that everything is pieced together out of rectangles. I had a sweater I knew fit me, that was already roughly rectangular in shape, so I used it as a guide for the height and width of my main body pieces, and also as a guesstimate for how to make the V neckline I was after:
I used the first few bits of the Fibonacci sequence (1, 1, 2, 3, 5) to determine how many rows deep to make my stripes. At the center point of the sweater I reversed the order of the stripes so the sweater is symmetric across the center of my torso:
I couldn't find an edging that would keep the neckline from stretching badly out of shape. So I made a "ribbon" of single crochet, 7 stitches wide, following the color changes in the body pieces, and used that to bind the edges along the neckline. I liked it so much I used it for the sleeves and the bottom of the sweater.