The persnickety issue is a separate matter ... I usually test my threads and the machine set up on some scrap batting/fabric til I think it's just right. Then I quilt a mug rug to test further and to get myself into doing it before I head for the "real" project! Use all the same fabrics, battings and threads for that test run, so you replicate what you'll be working on. Otherwise, you may get some surprises.
I'm somewhat a newbie at machine quilting and far from being good at this. I've tried different threads, but the finer threads are less noticeable when I make an "oops", and believe me, I have lots of those!!
Invisafil ... nice and fine ... and so far, I'm really liking it!