Market towards affluent wealthy neighborhoods and offer discounts if they let you clean their businesses they own!
Also, I would suggest up selling everything you can while you are there. I also put all my clients info into our QB and an email database and send an email around holiday seasons and every couple months or so with special discounts. People love discounts. People actually respond. We use Get Response but looking back I probably would have used Mail Chimp if I knew about it. I also pass out Magnets to all my Residential customers. Magnets really do end up on fridges. I have a magnet on my fridge from a Pest Control company I used 3 years ago! And don't get the thin magnets get the thicker magnet because I got the thin magnet and it doesn't really stick up on the fridge very well. But I get returning customers from driveways I cleaned 2 years ago from the magnets! Other than that, obviously Im big on online marketing towards residential customers. I wish I had some big secret to share but I don't. Just plugging away and working hard daily.
Hope this advice helped in some way! haha