My side project has been growing pretty quickly, and I'm making it my full-time focus. I'm the only owner (I do plan on having employees), I have no plans to ever raise money, and I'm a CA resident.
What's the best way to setup the company so as to minimize my tax burden?
California is an amazing place to live, but a lousy place to be in business. If you're not tied to your current location, the best advice you'll get is to get setup in Nevada ASAP. Your balance sheet, stress levels and sinuses will all thank you often and profusely if you do.