Before starting the weave, I used a framing square to mark the front rail where at the point where the back rail ends (the front rail is longer than the back on this and many chairs). This mark was where I wanted to hit with the first wrap of the weave. I started out on the underside and wove in my first two strands. I kind of just made this part up, so I don't know if it is right or wrong, but it seems to have worked fine. I pulled these first two strands all the way up to the last warp row at the front of the chair.