I have been teaching art almost as long as I have been an 'adult', whatever that means!
Art is a discipline, like most others; it requires practice, lots of practice. The ability to function 'adequately' in an art room is not different from how we develop skills in any other area. Mastery is another matter; it is the result of a conscious decision and a lot of hard work!
I teach each new skill, sequentially, building on prior knowledge. I have done this with students of all ages, from all backgrounds, with a wide variety of skills, abilities, as well as disabilities.
But art should also be pleasurable, whether making it or looking at it and learning to understand it. Artists need to be playful, curious, willing to experiment and take a risk here and there. But, to quote my very first education teacher from a long, long time ago.... "You cannot create from a vacuum!" OR... as I often say, "Learn to think inside the box... then knock down the walls!!"