Art is subjective, but learning art can be highly regimented. What are the best, most proven guides for learning how to drawfag?

These guides must:
>provide detailed instruction
>cover all relevant aspects of drawing, from technique to fundamentals
>articulate each step of the process, why the learning exercises/material were chosen over others
>have proven results. I.e. people who have successfully completed these courses and demonstrate the advertised level of mastery

Unfortunately there are a lot of grifters trying to sell you on a course, or even just people making shit up with no experience or evidence. You even get trolls intentionally misleading people, especially here on /ic/.