nanna-up-north--very pretty OBW. For laying out, I have seen them go from light to dark at an angle say starting in the top left with light and ending with the darkest blocks in the bottom right. It looks like you've tried to sort by light and dark, but that your light is in the top left, medium colors in the bottom left and dark more on the right...maybe thinking about it/looking at it as going light/medium/dark it will help with the laying out. Also once you have them sorted by shade, you can decide do you want dark back ground with yellow flowers close to the medium, them go to pink, purple, green...or do you want the flower colors mixed throughout the dark. Just some things I would try....