These were arranged working from a line of symmetry from top to bottom and side to side. I really just played with the layout on the floor until I found an arrangement that would work in the space. Hope this helps.

I agree. Arranging on the floor is the way to go. I have an online boutique of this type of plate and you can shop by size, color, or motif. I also have the adhesive hooks to make them easy to hang: http://www.decorativedishes.net