Optimizing quality (not quantity)
Many times, many businesses, services and freelancers try to do too many things.
Which inevitably means there are a lot of things they do that they are merely average (or mediocre) at.
Alas. If that's you, you should avoid doing those things.
In fact, the more you can avoid doing those non-essential tasks (so that you can optimize the most essential one) the better.
Because by focusing on the one skill you excel at, you create scarcity. And scarcity creates value.
By doing one thing well, you can create more value in less time. Serving the people who are willing to pay a premium for a scarce—masterfully executed—skill.
(A bowl of homemade soup, after all, is worth more than a thousand cans of rubbish.)