Using transparent PNGs (Patreon)
Content
I chose a light color to make it easier to see windows with a dark theme, then I resized the picture to fit the entire height of the screen and positioned it to the right until Borr looked in a good position and that's it!
For this one, I left the original resolution of the transparent PNG untouched, and I just dragged it to the right of the screen and into a good position, then I duplicated the transparent PNG and used the "add" effect on the topmost layer to make it look a bit more pale than the original picture and adjusted it to 50% opacity (the add effect is available on almost every picture editor under the layer properties option).
And that's it, you can make custom pictures and wallpapers, use text if you want, draw a background, it's fine... you can even make memes, I don't mind lol. The only thing I'd ask you not to do is to reupload it with minimal modifications and claim the original picture as your own, and that's it lol.