Drawbacks
• The background may appear darker than anticipated.
• Don't expect many sparkles.
• It may affect the overall image balance.
Negative prompt
dark background, black background, night sky, space background, deep shadow, underexposed, low exposure, vignette
However, these can also be advantages.
I’m making this public simply because it’s inconvenient to keep track of it privately,
but I personally expect to use it quite a lot for playful experimentation.