Compose for the screen, not the frame
For desktop, keep the visual weight low and to one side — 'subject in the lower third, calm negative space above' leaves room for menu bars and icons. For phone lock screens, prompt 'vertical composition, key detail in the center, quiet top area' so the clock doesn't cover the best part. Dark or evenly-textured zones behind icon grids keep labels readable.
Generate desktop wallpapers in 16:9 (or 21:9 for ultrawides) and phone wallpapers in 9:19.5 — matching the ratio at generation time beats cropping later.
Styles that work at wallpaper scale
Landscapes with atmospheric depth (mist, god rays, layered mountains) survive daily viewing better than busy scenes. Minimal gradients and abstract shapes are the productivity choice. For personality, anime cityscapes, vaporwave grids, and dark botanical macros are perennial favorites — and Nidhogg's aesthetic presets like FOREST MIST or VAPORWAVE GRID apply those looks in one click.
Build a matching set
The pro move is generating a coordinated set: same prompt, same style block, rendered in 16:9 for the desktop, 9:19.5 for the phone, and 3:2 for the tablet. Your devices end up looking like they share a design language, because they literally do.