As freelancers we often get caught up in how to find the best clients but once we have them, we don't consider that some clients may cost us more money than we earn from them. I have had clients who called me every 10 minutes when I was working on a design for them, asking, in effect, "are you done yet?" over and over. I have had clients who wanted to email me with ideas all day long, and if I didn't respond to them immediately they would complain that I wasn't taking them seriously. One memorable client wanted me to bill his company at a rate 75% lower than my normal rate. When I complained that that wasn't the rate I charged he said "oh, just submit hours so that you're paid the right amount." In other words, he wanted me to lie on my time sheet so that the company was paying me a lower hourly rate, but I was billing for more time than I actually worked. All of these clients I eventually fired, some more quickly than others. Why? Because by firing those clients I freed up more time in my schedule to work with clients that were cost effective.