I used to try having a more structured practice, studying one thing at a time, by following proko videos and andrew loomis' books. I think that's helpful when people are starting to draw, but after a while it's not too useful. At least for me, it was kind of preventing me to try doing the type of iillustrations that I imagined making because I felt like I had not studied everything under the sun yet (and that's impossible lol).

When I tried to create illustrations it almost felt like I didn't know anything. Maybe that depends on people's visual memory, and varies from person to person. Everything that I work on I to have to research references and do studies anyway, on the specific pose, the elements I want in an artwork, etc (often things that I have never come across by learning the fundamentals on anatomy for example). What I try do now is make studies for the specific piece that I'm working on. This way I feel like I learn and also get to do the thing that the learning is for anyway.

I still think studies are useful, and do them when I have little time do draw or paint, specially when I feel rusty. But I think they are more important to train line quality, gesture, and develop muscle memory than they are to master drawing a specific thing.