As a rule, it is more profitable to have a handful of big and busy clients rather than dozens of smaller ones. You can be more productive and efficient doing repeat business with familiar clients. There is no learning curve and less administrative and marketing overhead.

The more of these big clients in your portfolio, the greater your income. It works that way for every freelancer I know.
So focus 80% of your looking-for-business efforts on clients that need a lot of what you do. And when you get to work with one, bend over backwards and jump through hoops to please them.

If you have one such client, that’s good. Two is better. Three is about right. Instead of a fourth, try to find a bunch of infrequent clients, or small clients who might become big.

Because the one rule about big clients is this: They will go away. Through no fault of yours, things will change somewhere and the run will be over. So cultivate them when you can, and always have others in the wings. Always think about how you’d replace that big client.

Because you will have to. Guaranteed.