Once I completed the final sanding and prepped according to instructions, I applied Rubio's Monocote Pure to the frame.  It was my first experience using it, and while it was relatively easy to apply, I didn't like the final texture of the wood using their sanding recommendations.  It's a little rougher than I'd like.  Before I use it again, I'll experiment with doing some finer sanding.  But for this project, I left it as-is and got busy weaving.

I wanted a wide band of cords directly in the center of the seat, so I started weaving the warp cords (front to back) in the middle of the bench and moved outward.  This band will later be used to conceal knots underneath when I need to join lengths of cord as I'm weaving the weft strands (side-to-side).  The band of cords looks a little untidy at the start, but the gaps will close up once I begin the weft weaving.

This weaving technique uses cow hitches to reverse the direction of the cord as goes back and forth between rails (as opposed to the technique that uses 'L' nails on the rail).  It's a more tedious process because for each adjacent pair of cords, you can't simply pull a loop across, wrap it over the rail, and hook it over a nail on the back side.  Instead, a single cord has to be threaded around in order to capture the rail with the cow hitch.  This is explained well here (although there is a slight error in his diagram).

When using this technique, the gaps between the warp pairs are filled on one rail as you weave. 

On the other rail, the gaps are filled in a separate step after all the warp cords are finished.

This illustrates the purpose of the weaving slots.  Without them, there would have to be a gap in the warp cords because the leg would prevent the cord from being able to wrap over the rail.

My estimate was off for how much cord I would need to complete the warp weaving with a single length of cord, and I ran out a few inches from the end.

I started a new length of cord on the back side of the rail, with a staple anchoring the tail end of the short cord and the start of the next.

I left a short pigtail on the end of each that would get wrapped as I finished the remainder of the warp cords.  I later realized that this would have been a good place to pre-tack the start of the doubled weft cord so it would get wrapped and concealed as well.  I hope I remember that for next time.

And that finishes the warp weaving.  Again, I left a little pigtail end that would get wrapped on the underside of the stretcher when I start the weft weaving.

I've vowed to do a major workshop cleanup after this project.  I can barely move in here!

I then finished-up by wrapping the gaps in the far rail (no photos), and was ready for the weft weaving.  That's definitely the most satisfying part where everything comes together.