I've been cured of my fear of machine quilting, and all it took was the right materials.
I had been afraid to MQ any tops I was pleased with, or had made with expensive fabrics, in case I ruined them. So I practised on some 12" squares, which worked OK. Next I had a go at quilting an ugly 10-year- old UFO that had been in storage so long, and was so badly constructed that it was impossible to press the seams flat. In any case it was lumpy and bumpy because it was badly made. And I bought nasty cheap batting because I didn't want to waste money on it. In a nutshell, the quilting was a disaster, and I ended up (avert your eyes if you are easily upset) throwing it away. Honestly, it was that bad.
Next I tried to quilt a pretty but very simple top my sister had made and wanted turning into a picnic blanket. She knew nothing about quilting, and provided some poly fleece fabric for a batt, and some nasty plasticky stuff, like waterproof clothing is made from, for a backing. Quilting this was a nightmare, too, and I was starting to get really scared of MQing. I have a stack of nice tops I want to quilt that are oppressing me from their cupboard, but I was afraid to quilt them in case I ruined them. You see, I am such a lousy quilter. My 2 efforts to date have been dreadful. That proves it.
But then this baby quilt for my sister wanted to exist. It wanted it so bad, it pretty much made itself in 24 hours. No false starts, no mistakes, no unpicking. And it told me "I need to be quilted - this is how I should look [mental image]. You can do it. Now GO!". And I did, and it looks great. Well, not GREAT great, but absolutely fine for a beginner. No big nests of thread on the back. No tucks on the front. No ridges or bumps or gathers like I was getting with the lumpy top and the slippy plastic backing. Well, DUH!
So if I use 100% cotton fabrics front and back, 100% cotton batting, well-pieced tops with flat seams, I CAN MACHINE QUILT! Whod've thunk? UFOs, here I come.