I know a woman who teaches blind people how to sew. She has them tape a popsicle stick on the throat plate. Place the first fabric against the popsicle stick, then lay the second fabric on top and pushed against the popsicle stick.

I hope you find something that works for you!

My Mother had this and we would cut her pieces and pin them together. She then had sewed the pieces. Then we would pin those pieces together, etc. We did use narrow painters tape to mark where to sew. She got to be pretty good at this method.

I don't know if this would work, but what if you just drew a line down the edge of each piece with a washable marker of a contrasting color? You could easily do this when you cut out the pieces.