yes, is like a standard repetition method. The thing is that, for drawing, and any "corporal" related activity, you must learn to make the movements too, train your muscles to gain the ability. In guitar for example you can memorize all the theory, but you need flexibility and speed in your fingers, and coordination, and sometimes, in drawing is the same, you have to learn how to control your muscles and especially the coordination between your mind and the motor expression of your fingers, wrist, and arm, so you need to actually been drawing constantly for that.
There is not really any times or periods to make that, is literally try and error, the thing is that you have to be aware of your performance, otherwise you will never be able to correct or improve the things you need.
Some people just do it naturally, they have a strong natural affinity, others just dont have that, and need to think more.
Think of it as if you learned math, how long does it take to memorize a mathematical formula? Some people only try to explain to themselves the process by which it originated, to understand it, others just memorize it and apply it each time until it becomes natural to them.