Well, this is my first wallpaper, and it took quite some time. First, I started off with this scan of Eureka. I had to extract her from the background, which was quite time-consuming, and then I had to rebuild her missing arm. That was actually quite simple. After that came the choice of the background. As the anime is all about the sky, I thought a picture of some clouds will do nicely. After that, I used some custom brushes to create the swirls around Eureka, and did some smudging(with a custom brush) and blending. I added 2 more adjustment layers, and run my special script ^^. That was it.

Thanks for everyone's suggestions in Session Zero and in the forum as this was in progress. With your help, this wallpaper is what it is now.