I know that yardage usually stretches from seledge to selvedge, and does not stretch end to end. When I am cutting quilt pieces, I make a point of making sure I do not turn any of my fabric so it all stays the same orientation. When I am sewing, I make sure to seam the non-stretch edges first, then connect the rows using the more “adjustable” direction to join the rows matching the seams and letting the machine squish the stretchiness in. If I am cutting triangles, it is not so critical, but I keep my long edge facing up and down so it does not move, then I have less problem with not matching seams. My favorite pattern is TAW (trip around the world) byEleanor Burns. No seams to match at all.
