Copy your favorite artists. That’s the quickest way to learning how lines fit together in aesthetic ways. Obviously don’t take credit for anything you copy, but it’s definitely a 100% valid way to learn to draw. I did it, your favorite artists did, and the old great masters did it.
Other than that, there is literally nothing more important than consistent practice. It sounds anti-climatic, I know, but it’s the utter truth. Practice practice practice.
NONONONONONONONONONONONO DO NOT COPY SOMEONE’S STYLE. I DON’T CARE WHO DID IT AND HOW MANY, DO NOT DO IT.
You misunderstand.
Copying your favorite artists is how one LEARNS to draw. And ideally, one would be copying several artists at once. Overtime, a fledgling artist’s OWN STYLE will evolve from the cooking pot that held ingredients from others’ styles. And then you’ll find yourself drawing completely new stuff.
But there isn’t a cutoff point to it at all. Master artists will still look at their peer’s work and try to learn something from it, often by trying to emulate it.
This process is the most natural thing in the world. It’s impossible to NOT be inspired by other artists, and it’s been that way since the dawn of art. Frankly, it’s a lot harder to try and 100% copy another artist’s style, line-for-line, which I think is your concern.
The way it was worded was honestly poor. There are different ways to improve other than simply copying a style. I don’t like the idea of “copying a style” even if it is the most basic and natural thing to do (how to draw books enforce this use of stylization copy). Copying someone’s style allows their mistakes to fly over your head, especially if you’re looking to change your own style and improve.
Instead:
Draw from life, be it still or not. Draw rooms, groups, people, animals, buildings, whatever. Draw with scribbles or just lines. It doesn’t have to be 100% accurate at all. It is just practice after all.
Use references. Stock photos, general photography, life drawing sessions, yourself, character sheets, conceptual artwork. They’re all there, you just need to use them and draw what you see.
Emulate. Take elements of a style you like, or several but not the entire style. Otherwise it’s more likely to be considered theft and can potentially lessen your interest in a user who inspired you that uses that said style. This part here is what I’m going to guess that you meant, but again the wording was relatively poor so it was subject to literally mean copy/trace.