There seem to be a lot of posts by weavers who are (understandably) hesitant to cut into their beautiful woven fabric. I am not yet a weaver, but I've sewn for decades and my last project - a sashiko stitched top (embroidered with running stitches) on a somewhat ravelly cotton fabric also caused me some hesitation - especially since I needed just about every inch of fabric. Here is what I did:
I already knew that my pattern would fit, so I made full size copies of the front and back pieces on Swedish Pattern Making Paper, which is sturdy, flexible and somewhat transparent and comes on a large roll. I laid those pieces on my fabric, and when I got the placement I wanted I pinned the patterns in place. Next I outlined outside the pattern margins with a sliver of soap (it works great for temporary marking!) I allowed a bit extra when possible in areas I was not sure of (like the neckline). Before cutting anything out, I took the whole piece to my sewing machine and carefully stitched around the outsides of the outlines - to protect both the fabric edges and the hand stitching. Once that was done, I cut out the pieces, using a rotary cutter for the straight edges. Next I took the two garment pieces to the serger and serged a three thread overcast on all the edges, trimming as little as possible. If you don't have a serger, an overcast stitch or a multi-step zig zag stitch will also do the job - but the serger does make a neater long-lasting finish. Finally I sewed it together, tweaking the darts to fit, etc. I was able to piece together a few scraps for facings for the neck and arm holes. The serging makes a beautiful seam finish and works best with the seams pressed open.