Select a collection of fabric scraps (as usual, I prefer sheers, but it's up to you) and blend across the spectrum like this:
When I put this piece together, clearly I was thinking too much "blend" and not enough "lace."
So to get a lacy look afterwards, I heat-distressed it just like the previous piece. This almost worked, because nearly all the fabric was synthetic. I had, however, used some hand-dyed green/aqua silk to make the transition from green to blue. That's the big ugly brown spot in the lower left. And that is why it pays to think about what you're going to do next with the piece, and what type of fabrics you want to use, before you get the wrong stuff neatly stitched into the grid!