Set up a “restroom maintenance” route that services public restrooms by cleaning toilets and sinks, refilling paper towels and soap dispensers, providing air fresheners, and mopping floors. Clients might include restaurants, grocery stores, gas stations, and big box chain stores, among others. Once you get a business like this started up, your clients will be happy to provide testimonials, particularly as it’s a distraction to the staff they pay for retail work to do cleaning. You can earn about $300 a month per client, so a route of just 20 clients or so will make his a pretty lucrative business.