How do i clean tv monitor properly?

Screen off and cold first, partly so you're not wiping a hot panel and partly because you can actually see the smudges on a black screen. Dry microfibre cloth, light pressure, wipe in one direction. That gets most of it. If there's something stuck on, dampen a corner of the cloth with distilled water (tap water leaves spots), wipe, then go over it with the dry side. Never spray anything straight onto the screen, it runs down into the bezel. And skip glass cleaner, kitchen roll and anything with ammonia in it, they can strip the anti-glare coating and you're left with a patchy screen forever.