Hi there,
When I made this quilt, shown in my avatar, I cut out & made all of the Iris blocks first. Then I made the other blocks & put it together. On another quilt, that had rows of identical blocks, I cut out & sewed all of the blocks in that row. So, it just depends on what you are working on. I do like the assembly line way. Now, I am doing a BOM & all of the blocks are different!! :D