Here's what I did: I billed in advance. Seriously. It takes all the pain out of billing. It reinforced proper project scoping and developing meaningful and tangible deliverables. And, most importantly, the people who agree to work this way are COMMITTED to the work. They are responsive, engaged, and get you answers to your questions right away. Best of all? It increased my workload. I lost a few clients, sure. But they were quickly replaced by others who respected me, and valued my work. My finger hovered over the "Publish" button that night, let me tell you! I don't think I slept a wink after I pushed the changes out to my web server, and proclaimed to the world that they had to PAY ME FIRST before I'd work with them. No freebies. No free consultations. Just demonstrably good work in my online portfolio, and the price list. Bam. That's it. It was scary, but it was effective.