Your quilt is unique and lovely. PLEASE don't meander all over it and lessen the impact of the design. Your quilt stands on its own design and to overlay it with a lot of stitching would be sad! You could start under the upper left 2 diamonds and go straight down to the next diamond on the right and cross over just under it and down and over under the next diamond on the right, etc. Lay threads out and see if you want the neutral color or one of the colors in the quilt design. Actuall, I always start my quilting in the middle of the quilt and work outward (keeps everything in line), but that wouldn't change the quilting design.