Performance considerations

Measure the frames your project will actually render. A small planet in the distance and a shell filling the whole screen can have very different costs.

If the shot is expensive	What to compare
A large atmosphere fills the frame	Compare the shell enabled and disabled. If the shell dominates, lower Steps I or Steps L on a copy in small steps and inspect the limb for banding and instability.
Several rings or corona plates overlap	Compare the full stack with optional layers hidden. Transparent layers can shade the same pixels more than once. Keep the original stack as a visual baseline.
Fine terrain detail shimmers at distance	Check texture mipmaps, tiling and filtering. Judge the change at the final camera distance and output resolution.
A shadow-only ring is expensive	Compare with its caster disabled. Keep the shadow distance only as large as the composition needs.
A scene slows down with multiple cameras	Profile each camera and its HDRP frame settings. Compare shadowing, sky, post-processing and exposure separately from the materials.

Use Unity’s Profiler for frame cost and Frame Debugger to identify which objects and effects are drawn. Compare the same resolution, quality level and view. Use the actual target build for a final check. When scripting a material effect, reuse a material copy while the effect runs.