It depends on what I'm doing. I often make crumb blocks (I call them slice n dice blocks) that don't appear to be all that controlled, but I like to put the blocks into modern quilts with lots of solid (usually lights that read as white or light neutral) color between the blocks. The quilt itself ends up looking pretty controlled even though the slice n dice blocks aren't.
Otherwise, I pay attention to value, scale of patterns, color, etc. while piecing the blocks, even when I'm making scrappy quilts. For me scrappy doesn't necessarily mean giving up design control, it just means using a wide variety of fabrics--and most of my scrappy quilts do in fact come from my scrap bins, but I have no problem supplementing them with other fabrics from my stash.
Rob
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