They must be probed, examined, sharpened, and used in all their forms for a writer to write well and be successful. In reading you discover all the forms you know, and more that you didn't. Read widely and read much. Take advantage of this free schooling. Read for pleasure, yes, but study what you read.
Writing is a way of life.
A few years ago a study came up with the astounding statistic that the average man can't go fifteen seconds without thinking about sex. I don't know if that is true, but I do know that in my own life I can't go more than a few minutes without thinking of writing. It's a constant awareness, a way of life. However, you can increase the chances of your being successful at writing by making writing a way of life. Writing is a mindset, a psychological view of life.