One of the most useful ideas I've come across is Ray Dalio's idea re: designer vs worker level you.
He recommends thinking of yourself as a worker operating in a machine that you've designed, and says it's important to distinguish between you as the designer of your machine, and you as a worker within your machine.
"It's much more important that you are a good designer/manager of your life than a good worker in it."
That's not to say being a good worker isn't important (Dalio also says good work habits are way underrated), but it's not as important.
"To be successful, the "designer/manager you" has to be objective about what the "worker you" is really like, not believing in him more than he deservers, or putting him in jobs he shouldn't be in. Instead of having this strategic perspective, most people operate emotionally and in the moment; their lives are a series of undirected emotional experiences, going from one thing to the next."
For example: for a long time, I had been getting up early (and staying up late) to hack away on side projects (which I always faintly hoped would at some point take off) but found once we had our second child that that was really hard to do.
So I decided to go down to 80% at my day job to spend one day a week working on my own stuff. I viewed this as a "designer level you" move, vs just continuing to hack along harder and harder (and with less and less sleep) in my role as "worker me". My first project made more than 20% of my old salary, and helped me take the leap to working on my own projects full time.