I'm not saying that this is the best or only way. I have lots of friends who go to 100% every time and they are extremely prolific and effective creators. And they make things that are better than the things I make. I also am not trying to say that I don't think the stuff I make is good, I think "good" is a combination of time, skill, talent, and ability to choose and understand your own objectives. I just shave on time spent and do my best to optimize the other stuff.
This is what I do, not what I suggest other people do.
In general, when people try to sell you on some life-vision for being an ULTLA EFFECTIVE PERSON, what they're really trying to do is make you feel like you haven't accomplished enough or aren't awesome enough, and thus need them to become the thing you should be but which you're being held back from by some lack of knowledge. I hate that shit so much, and I really hope I'm not doing it here. Every person will find different ways of doing things that help the world and other people, which is the important thing.
But...don't let perfection hold you back from making things or doing things. Revel in your imperfection, because perfect doesn't exist.