How do you set up/configure your Billing/profit margins? I've been flipping this about for some time and have worked with several different formulas, and it seems that every client is so unique that to charge an hourly rate doesn't seem to work for them, and the same for doing a percentage based formula. One client you can put in an enormous number of hours, and you don't want to charge for every moment if it is within the "fine tuning" of a design, while the same can be said for the percentage based formula... Is there a magic wand that you can wave and help me out here? What is the best way to bill client, and separate profit, from that formula???