More on wallpaper resolutions

For my recent Escaflowne wallpaper, I decided to try a different approach to the issue of cropping for various monitor resolutions. Usually I design an image as widescreen, and then crop off the sides to fit 4x3 and 5x4 monitors. This is not a very good solution, as this often means nice details are in danger of getting cropped. This time around I tried to overlay the 3 different resolutions, so the widescreen gets a little cropped off the top and bottom, and the 5x4 gets a little cropped off the sides, but this way less is cropped total.
What do I mean?

[Note: this was an in-progress version of the wallpaper in Illustrator, back when I thought I'd make it predominantly blue.]
I think I shall use this method from now on.