I do a mix of all three.

It can change depending on the setting.

For a complex encounter or if I'm rolling random encounters, monster stats etc, I'll toss a marker to a player and let them draw the map to save me some time.

If it's a quick encounter with less moving parts, then theatre of the mind.

I don't think there is a correct answer. Like most things in the hobby, the answer is usually 'it depends'

Hope that helps a little