I detest flyers and when I get one, on my door or card, I trash them immediately. To my mind, someone using a flyer is just tell m,e they are not a very good company.
I keep business cards in my purse all the time. I also use magnetic door signs. I strike up conversations with people I meet, in stores, doctors offices, etc. I had out those cards. Most of my work I find online. And because over 3 years I have built up a solid and very good reputation, I dont actually NEED to find new customers often. I believe that earning yourself a great reputation - and you do that by going the extra mile for customers - is your best way to build a cleaning business.