Solved my problem when FMQ'ing on dark fabric!
I am so excited! I've been struggling to fmq with a dark thread on dark fabric. Drove me nuts because it was so hard to see the pattern. Finally figured out a solution that works for me...hope it will work for you too!
I now take a piece of WASHABLE sidewalk chalk (by Crayola). I rub the side of a contrasting piece of chalk on my black fabric and WOW...I can actually see where I've sewn and where I need to go next. I always wash my quilts after they're finished and the chalk totally disappears.
Hope this helps!