I use a walking foot. I do not do fancy machine quilting like feathers, hearts, waves or whatnot. Mine is simple in the ditch and maybe, just maybe an echo or two..
I have found that if I start in the center with a seam across, then go the opposite direction ( kinda like North to South, then East to west) If i take the time to re-pin the quilt...I get excellent results.
I only pin the area I am sewing on, then re-pin...smooth, then baste (re-pin)
works for me... and if I am doing a large quilt, well, I cut it all down into managable squares...starting from the middle..
Hope this helps
K