That's what I normally do, I do straight stitching with my walking foot, usually in the ditch, but it depends on the quilt, you could just quilt horizontally first since your vertical lines would be zig-zaggy. Then I fmq in sections, usually from bottom to top so that I can more easily keep track of where I've been and where I'm going to. I start in the center and work my way out, only because the center is the hardest to work on because of the bulk of the quilt and I want to get the hardest part out of the way first. I'd suggest free form swirls or loops, you can make them in varying shapes and sizes and it doesn't look like a mistake.
Originally Posted by Elisabethann
Someone suggested SID for the long lines across just to secure it, then try the FMQ, in sections. Any thoughts?