In my last post I mentioned not having a contractor's license. One comment cautioned against performing installations without one. So I thought I should take the time to clarify that point.
The work around for me was simply to never do any onsite work outside of maybe going back to the job site to make small adjustments or do minor touch-ups. Contractor laws vary from state to state but here in California the law prohibits you from doing any work with a value over $300 without being licensed. In the beginning, I separated the installation and often times offered the installation as a free service. But that did not work because the law binds any onsite work to the contract.
Ultimately, I quit doing installations altogether. Either the general contractor took responsibility for the installation or I worked out a separate arrangement with a one of several subcontractors with whom I developed working relationships. They contracted directly with the clients and I provided any necessary oversight.
Not doing installations might have cost me a job or two but I simply did not want to end up being a contractor and being bound by laws that made it almost impossible for me to work out my own payment arrangements. By staying out of the contracting business, I was able to finance my jobs with the customer's money instead of my own.