For clearing it quickly and stopping it coming back, the thing most people do not do: use the air conditioning in winter.
The compressor dries the air. Running it alongside the heat gives you warm dry air rather than warm damp air, and it clears glass far faster than heat alone. Most modern cars engage it automatically on the windscreen setting, and plenty of people turn it off in winter thinking it only makes things cold.
The full demisting method:
Air conditioning on, heat up, fan high, on the windscreen setting.
Recirculation off. This is the one people get wrong. Recirculating keeps the damp cabin air going round; you want to draw in outside air, which in winter is much drier.
Open a window slightly for the first minute if it is very bad, which vents the moisture rather than moving it about.
And two preventative habits:
Clean the inside of the glass properly. A film of residue gives moisture something to condense on and makes wiping smear. A clean screen mists noticeably less.
Do not leave the car with a wet interior, and crack a window for a few minutes when parking somewhere sheltered after rain.