if you are knocking doors then the weekends or at night, which is a bit obvious really but if you drop flyers which I suggest, then they will see it whe they get in. I agree get out every day, even if its just for a half hour.
You could do both knock on door and flyer drop, but I wouldn't. People tend not to like that approach and you tend to end up like a recorded message. At least with a good flyer, you get a consistent message across.