My grandmother mostly made wool quilts. Out of thrift store finds, too! She seemed to find a lot of wool skirts. I remember helping her trace her cardboard squares out on them as a kid.
She would machine wash everything on hot before cutting. Anything that failed in the wash (ran, shrank too much, etc), did not go into a quilt.
Her designs were mostly very simple. Trip around the world, or basic checkerboard. I can't remember what sort of seam allowance she used, unfortunately.
She used cotton batting, and oversized flannel backing that she wrapped around to the front to serve as binding. Her quilts were all tied with yarn instead of being quilted with stitches.
I have one on my bed now that has been used every winter since I was a teenager. It's too small for our bed but we lay it crosswise and use it anyway because it is SO warm. I love that quilt! I machine wash it when it needs it and it comes out looking great. It does have a hole in the top, something snagged a square several years ago and put a rip right in the middle of the square and I haven't fixed it yet. (It holds up fine, even with a hole!) My grandmother always patched her quilts with whatever was at hand - I have an older one that belonged to my uncle, it's patched with his old boy scout patches! I need to find something in the similar spirit to patch MY quilt with!