I ask for payment upon completion, when you're happy, nothing up front. I would much rather do a complete, thorough job with every checkbox ticked regardless of how long it takes. If you have ever been called nitpicky or demanding and accept nothing less than perfection in your life and property, you and I will get along just fine!
On top of being OCD about the quality of my work, I actually enjoy looking over my results. I also like being able to set my own schedule, as a self-employed sole proprietor with no employees I have the freedom to take all the time I want to make each job live up to my own expectations. Please look over my website at paintdoctormd.com to see my previous work, I've even created several YouTube videos showcasing my work.