Sashiko quilting is very similar to "big stitch quilting". Sashiko uses a white thread - reminds me of what we used to use for candlewicking, sort of like a crochet thread #10 wt. - and the quilting designs are rather organic, specific to Japanese fabrics and symbolisms.
In the nineties, my shop often taught classes on "big stitch quilting" and found many used it in quilts made of Civil War reproduction fabrics, among other things. It became very popular. The designs we used were just like any other regular quilting design -- feathers, waves, grids, flowers, outline, etc.
I now usually use only the big stitch method because I have enough nerve damage in my hands to make feeling the needle a bit of a problem. With big stitch I can use a larger, easier to hold needle and thicker threads.
I've quilted with crochet #10, perle cotton balls, and Sulky cotton 12 wt. I prefer the thread to compliment/contrast the fabrics and cause the quilting patterns to add to the texture and patterns of the fabrics, to be very noticeable rather than somewhat hidden in the quilt.
My needle preference is Richard Hemmings large-eyed betweens in the 3-9 size packets. I use the larger needles in the packet.
The thread allows 5-7 stitches to an inch rather than aiming for the master standard of 10-12 stitches. As always, consistency of stitch is more important than stitch length.
Wish I had good pictures of the quilts I've done, including one that was a commission for a lady who had done beautiful candlewicked blocks several decades ago. She was thrilled with the look of it.
Jan in VA