1
Inspect and preserve the source
Open the original at the size where it will be used. Note whether the main issue is noise, blur, low contrast, or insufficient dimensions, and save an untouched copy. For a private image, consider whether sending it to any online service is appropriate.
2
Request one restrained change
Describe the subject and the defect in plain language, such as reducing low-light noise while retaining facial texture. Follow the destination's available workflow; a text prompt, upload control, preview, or particular format should not be assumed until it is shown there.
3
Compare before keeping the result
View source and result at the same zoom. Check edges, text, faces, and smooth areas for invented detail or waxy texture. If the change is too strong, revise the request or return to the original rather than repeatedly processing an already altered copy.