I think most of us focus on the things we enjoy. (I love to write.) And you get better and better at something with repetition.
But the same is true of things that you don’t enjoy.
I love writing, but in my own style, free form. I NEVER liked diagramming sentences, and, like the poet e.e. cummings, I believe rules were meant to be broken.
HOWEVER, I have a goal of working for PAY as a freelance writer, and freelancing is all about following the rules, especially grammar and punctuation. So, I find that to keep from limiting my success, I have to learn to become a stickler about the rules of writing for pay.
Like Steve asked in his article: Where are you limiting your own success? Find one thing and focus on improving it this week.
It was difficult for me at first, especially since my brain cells are not NEW anymore!!! But I’m finding that I’m enjoying becoming more adept at the rules.