Just as every homeowner wants to be buddies with an Electricain, every Electricain should be buddies with a Lawyer. It's an unfortunate part of doing business these days.
The last time I was burned (about 3 years ago), it was for $30,000. I made the mistake of trusting the homeowner on a build, and perfroming extra work without writing up everything. It was a learning experience that I would hope to help others avoid.
Keeping your "ducks-in-a-row" is paramount. Keep your paperwork clean, organized, and SIGNED at every step. Give your clients 30 days to pay, or make arrangements to pay, any invoice that you have submitted, or cease work. A months work, gone unpaid, can easily bury a small business.
When a problem occurs, have your Lawyer shoot out a request for payment. It usually drives the point home better than your word might, and it saves you the stress.
Just like the other guys you hire, your Lawyer is "on your staff" to save you money, increase profit, and make your business run smoother. Allow him to be a "wrench" in your "business toolbox". Pull them out when they are the right "tool for the job".
I have chummed up with my Lawyer - I've done some work at his house, and he actually helped me move a couple of years ago. A little money spent for a letter or two will save you quite a bit of loss in the future.
Did I mention keeping your paperwork tight? It bears repeating...