A trick for minimizing waste with handspun warps is to use a "waste warp". A strong yarn is tied to the back beam and threaded through the heddles. The handspun warp is threaded through the reed and tied to the waste warp, one thread at a time. The waste warp can be reused. The handspun warp can be woven, theoretically, up to the knots that join the two warps.
When the threading is done, the warp is beamed, as usual, and the weaving begins! My waste
warp is the waste from my curtains. It was already threaded in a twill variant. I played around with the treadling to get a different pattern for this project. I think this fabric will be felted, due to some long floats, and then turned into a bag. The yarn is a friend's handspun.
Here is the draft I am using. The long floats occur at the sides of the three dots. Hmm. I'd point to them, but that doesn't work! As you move to the left from the tie-up square, the threading is: 12343214. Follow that second 4 down into the drawdown of the draft and there are three black squares. To the left and right of those squares are the long warp floats.