We thought we'd paint it one dark shade of blue, but the test patch we did showed us it was far too dark. It was decided that we'd have stripes instead, so I measured the wall and planned the design on the computer, then taped up the stripes on the wall. (I did it properly with a plumb line - I was so pleased with myself.)
The next image shows the whole wall, complete with the dark patch of test paint - which proved hard to cover up. The room is small and this, the long wall, is ten feet long.
I chose three shades of blue to paint the stripes, and started with the darkest. This is how it looked after the first coat of paint.
Then, two more coats of paint on each of those colours later, I was ready to remove the tape.
The hardest part proved to be filling in the remaining spaces with the last colour - a light blue that was a close match to the paint used in the rest of the room. However, I am pleased with the end result and besides a little touch-up work still to be done, I'm pleased with the result overall.