Glue baste! When I prep my strips, I fold and press one end to a 45 angle (the same one on each). Then I glue baste it, press it, pin it to be sure it doesn't shift. My vision isn't the best, so I often draw a chalk line on the fold line so I can see it better. Then I sew it, gently tug it to release the glue, and after that I trim it to 1/4" seam. I press those seams open. I fold/press the binding in half and attach it to the quilt starting about 6-8" from the first folded end.
I basically finish the last join the same way. I unfold the first end, overlap it on top of the remaining strip, draw a line where the folded one ends. Then I measure over 2-1/2" (or whatever your starting width) overlap and draw a line. Once I double check it, then I cut and glue baste that last seam.