Power off the phone
Unplug any cables
Wipe the screen with a dry microfiber cloth
Lightly dampen the cloth with distilled water if needed
Wipe again with the damp cloth
Dry the screen immediately with a clean microfiber cloth
Use a cotton swab for edges and corners
Avoid spraying liquid directly on the phone
Avoid paper towels or rough fabrics
Avoid harsh cleaners, alcohol, or ammonia
Repeat with a clean dry cloth until spots are gone
If spots are under the screen or won’t come off, seek repair service