It's a common misconception that good customer service means a business must bend over backwards, to their own destruction even, to please an unreasonable person.
Examples of poor business respect includes clients standing outside your residence at night while demanding they need your help, calling or texting your personal cell after your business hours or repeated promises of payment but not following through. All of this is forms of discourtesy. As a human being, you have the right to be treated civilly. Don't accept this type of behavior from your customers and be sure to establish firm boundaries from the beginning. This is especially difficult for service individuals like plumbers, housekeepers, seamstresses, architects, etc.
Make your hours of operation clear on your website and social media outlets and don't deviate from them. Never give your personal cell number to any client. And be firm, no matter how insistent the customer is. You must retain a level of personal distance for your own respectability and sanity.