According to Real Simple, the Mr Miyagi ‘wax on, wax off’ method doesn’t clean properly because it re-deposits dust and debris from your cloth back on to the surface of the mirror, which results in streaks.
For the cleanest results, you need to wipe “in a tight S-pattern from top to bottom”.
And if you’re a fan of paper towels, you’ll want to ditch them, too. Real Simple suggests you use a soft micro-fibre cloth.
The last thing you’re doing wrong? Spraying your mirror directly with glass cleaner. Apparently, this allows liquid to seep behind the silver coating and create black tarnish marks. Instead, spray on to your cloth first.