I wipe down my tools when im done a job and clean them with brake clean or spray nine (apparently its so good it kills HIV, says so on the bottle) about once a month. Im a field mechanic thats always on the run, i cant spend an hour everyday polishing the tools i used that day.
Lots of people like to use WD40, it can clean and prevent rust but i wont allow it in my service truck, i use a penetrating oil or a lubricant spray but dont use the jack of allspray WD40.
The biggest prob i have is my impact sockets rusting in the rain/snow rather then overly dirty tools, i wish i could find a solution to that