I think Steve Jobs said the only way to be great at what you do is to do what you love. And I would add the only way to really amp up your income is to be as great as you possibly can be at what you do, and always look to be better.

I had a couple jobs I took mainly for the money. They were soul-deadening. Maybe some people can handle that, but for me it's a recipe for burnout.

The interesting thing is I made, by far, the most money running my own company and doing work I actually enjoyed.