How to use background effects

Open Customize, find the Background Effect dropdown. Options include Aurora, Mesh, Particles, Geometric, Spotlight, Waves, Rain, Snow, Plasma, Dither, Night Sky and Old TV.

Aurora looks great on a dark gradient. Night Sky pairs well with a city image. Rain or Snow feels seasonal. Try a few until something clicks.

Effects render in CSS or SVG so they are light. They still cost a little. If you target older phones, prefer Mesh, Geometric or Dither over Particles or Rain.