You may have seen this Venn diagram called “how to be happy in business.”

I like it, but with one teensy-weensy criticism. The intersection between “What We Do Well” and “What We Can Be Paid To Do” is called “Learn to Say No,” because it’s something you don’t want to do.
The name of the diagram is “how to be happy in business” as opposed to profitable, but most people are happier if their business is profitable. So when you’re starting out that intersection should be called “grin and bear it.” Once you’re profitable you can call it “raise your rates.” I wouldn’t say “no” unless I had more work than I had time.