Sharp article on Forbes describes how to become smarter. The author explains some of the steps the brain takes to adapt towards certain behaviors, thought patterns, and capacities. You basically apply focus to pursue a certain direction and sustain it through practice. Whatever you find yourself doing builds the mental state in that direction.
You do have to meditate somehow and regularly. Not necessarily meditation where you sit on a floor, legs crossed, but a general habit of waiting quietly often and thinking on purpose about your life. What you understand through what you view in your mind is what you have to strive towards. Allowing your mind to wander aimlessly is both fun, natural, and healthy but needs to be balanced with times of focused attention.
Good quality can take the form of what you think, to what extent, and how well you execute thoughts into action. Nothing I have stated guarantees good quality or good quality all the time. As living creatures we are prone to blind spots and error. Rather, study, practice, and extra effort necessary in alignment with your developed inner view raises the probability of good and satisfactory thought and action over time. That is one way to obtain a higher performance mindset that echos out into actual higher performance.