Laying Out the Presents Quilt

Something I read somewhere a few years ago forever changed how I lay out my quilts. I still lay the blocks out, play with them, rearrange and turn them about until I like what I see:

Then I do the additional step of taking a picture using my phone's black and white filter so that the quilt is rendered in grey scale. This enables me to tell how the color values are relating to each other. Too many darks clustered together? Too many lights?

It seemed like there were a lot of light and medium blocks with just a few darks hanging out in groups. This surprised me as I felt that there were a lot more dark fabrics than lights until I took the B/W pic. So I rearranged some blocks and took another B/W:

This is how it looked in color:

I still want to mess around a little more before I sew them together. I really like the way the red bows stand out and there are four different pink prints for the other bows. The white block backgrounds were from an assorted white on white print jelly roll using a strip for each block. Of course I have to obsess over none of the bow prints or background prints being next to each other, but the black & white pics will help me make my final decision.

Have you ever used this technique? What other cool things do you do before you start sewing the blocks into rows?