My board is very simple, a piece of plywood covered with batting and flannel. In fact, I think the flannel was from a crib sheet from our children - I can't remember! If you don't have one, laying things out on the ground works also. What really helps me the most, is using a door viewer - you know those peep holes in doors so you can see who is on the other side? By looking through it, you can see your quilt from a distance and kind of get a feel for how it looks as a whole.
I played around with the block placement and then made the following changes. The large block in the second row had a red square center, but I really needed to add more light tan, so I partially ripped up that block and changed the center. The skinny block next to it was an unknown. If you look closely, I actually have folded fabric pinned (and the center isn't straight as it is just sitting there) as I auditioned different fabrics before settling on this combination.
Finally, I didn't like how the skinny block on the bottom row turned out - with the center more horizontal than vertical. So again, I ripped out the center seams and redid them so the red center was more vertical. After making the final block, I will piece them all together.