I'm right handed so left to right in the front feels natural. You can go either way. I have a computer on my machine and it quilts in both directions with no problems not even thread breakage. I think what sewingpup has hit the nail on the head, moving the machine smoothly in both directions should work fine. If you thread breaks going right to left, slow down a tad to reduce needle flex. I use a neutral thread on quilts with a lot of colors (unless it's super custom), usually gray, linen or mossy green.