When do you breath at your best? Is it when you are hell bent focused on breathing in the most effective way or when you are not even aware that you are breathing. There aren't many people who would give the wrong answer for that question. So let me ask yourself why do you think it's better to put an effort? You need effort. That's true. But for what do you need effort? Shouldn't you be putting all your effort to make sure that you won't have to put an effort ever again? Isn't that the most efficient way to use your effort? Can you show yourself a better and greater effort than the effort to put all effort to rest? So what should you try to do?
If you try to think about the stuff you learned about breathing at school, would you be able to breath properly? Isn't it the same with walking, swallowing, kissing, blinking and all the sensitive everyday stuff you do? I can give you a long explanation. But I'm gonna be heuristic and let you figure out the reasons through your own experiences. You should already understand (at least partially) that effortless actions are the most efficient and the optimal and the only way to bring up the best in you. Now shouldn't you go and put some effort to get yourself into the best track and make sure that you'll be the perfect and optimal; all by your nature?
Trust me. Just let your brain do the calculations. It's better than any super computer on Earth. Don't intervene the process. Just be the user; not the processor.