All you need to be supremely good at something is to just do it. It's that simple.
The problem lies in the misconception that becoming great is about doing great things, that the quality of your output has to be outstanding. School taught us to be afraid of not being great: poor quality results in bad grades, and bad grades result in suffering. Real life is different. There is no curriculum. Life is entropic. What works on a given day for a given person in a given situation might not tomorrow. This is why education is a process of experimentation at heart. You need many iterations to come up with some form of truth. Quantity, over quality.
But quantity is not enough either. Our bodies are aligned with the 24-hour window we call a day. In order to tap into your full biological potential, you need consistency. Consistency has a much deeper effect than the quantity or quality of your work, which is why you need to develop habits. A daily habit is easier to develop than a weekly habit because there is no willpower involved. No calendar to check, not much output quantity to cram into a few given days: daily habits are more achievable. This is why 200 words are the limit on this website: just enough to write something meaningful.
If you want to improve your writings, keeping your day streak alive is the best thing you can do today.