I have actually made only 4 quilts, start to finish, and am working on 5 and 6.
I went for lots of triangles on 6 and found that stitching in the same direction when sewing the same pieces helps.
I turned the fabric over and changed my thread (light with light/dark with dark) so I could do that and mostly tried to stitch so that the stretch was pulled in and not out.
If that makes sense.
It made a HUGE difference when I started putting the triangles together.
I was NOT careful about which way I cut the fabric (with the grain or across the grain).
The quilt is not finished yet but the piecing went better than I had hoped for.