As it is raining today, I apologize for the color of these photos (the incandescent lighting gives a yellow cast), but here is the current state of sweater progress. I have divided for sleeves, after reaching my target number of stitches, by folding the square in half along the shoulder lines, then marking every 14 sts and picking up at the underarms to make a mitered square from the 4th group of stitches from the corner. In my enthusiasm to knit this, I forgot to take photos of that process. Oops. In the upper right, you can see a folded square hanging off which becomes the bottom of the sleeve. In this design, I discovered that I could make a little underarm gusset by joining ( in a 3 needle bindoff) a group of sts on the diagonal section between the body and the arm. I think this will give a better fit and slimmer arms.
Here is a photo of the back:
I was clever here to get the colors to line up symmetrically on this row of mitered squares, but I'm sort of going for a random look, so on the front I'm letting the colors fall where they want.
Here you can see how the fronts relate to the back row of squares. I started at the underarms, and worked downward from there, as I wanted the center lines of the squares to be vertical. In this sequence, I can pick up along the sides of one square, and use the live sts from the straight portion, one group of 14 sts at a time. The only sewing is at the center back corner., where I must join the edge of a square to the corner. Sewing it gives a neater join than picking up and K2tog at end of rows, I think.