The order of operations that stops streaks
Power the device off, or at least turn the screen to black, because you cannot see what you are removing on a bright display. Let it cool if it has been running hot. Start with a dry pass: fold the cloth in quarters and wipe gently in one direction, top to bottom, to remove loose dust. Skipping this step is why people grind grit across their display and then find fine scratches later.
For the marks that remain, dampen a corner of the cloth with distilled water — damp, not wet, and never spray liquid directly onto the screen, where it can run into the bezel and behind the panel. Wipe in overlapping strokes, then immediately follow with a dry section of the cloth in the same direction. The drying pass is the secret. Anything left to air-dry is what becomes a streak.
Stubborn spots — dried splashes, something sticky — respond to patience rather than pressure: hold the damp cloth against the mark for a few seconds to soften it, then lift it away. Pressing hard on an LCD panel can leave temporary bright patches, and on an OLED it is simply a bad idea.
Phones, TVs and the bits around the screen
Phones are the dirtiest screen you own by a wide margin, since they travel between your face, your hands, your bag and occasionally the bathroom. They are also the easiest to clean: dry microfibre pass, damp corner, dry corner, done, ideally once a week. Take the case off while you are there; the seam where case meets glass collects a startling amount.
