Here it is, the final product!
Mounting the tiles to the wall was relatively easy. I decided to use this Duck brand mounting tape. It ran me about $5 for a 15' roll. I cut small pieces and used 5 for each tile (one piece in each corner and one in the center).
First thing I did was measure the center of the bed and used a level to draw a vertical line to match the first tile up to. For each row I started at the center and worked my way out.
And this is what it looks like completed without the pillows covering the bottom row.