I once did a quilt with antique blocks of varying sizes by adding log cabin strips to make it the size I wanted. I had very small blocks I arranged together by adding small sashing to meet size requirements. Alternate solid colors, maybe repeating colors from the blocks, in squares may help you. For zigzag, I can't seem to visualize that. We did a quilt in a quilt class where we sewed columns beginning with a full sized block and the next column with a half block ending w another halfblock and thus avoiding matched corner seams and it sh accomodate different size blocks and if necessary adding strips to make uniform sized blocks at least to the widths.