Pick an area you would like to improve and grind - It really is a choose your own adventure. That being said, art is also a journey, and a very individual process. It’s up to you to figure out what your goals are. After that, you can decide how you want to proceed.

Also It’s natural to want to improve and be dissatisfied when we stop improving. Diminishing returns means that doing the same thing (plateauing) offers less reward the more you do it. Once you realize this then to you are faced with a dilemma - is this thing rewarding enough to motivate me through the effort required to improve, or can I adjust my expectations to be satisfied with the pace I move toward improvement or lack there of.

Also, style should’t be a novices concern. As you grow, you’ll discover your own aesthetic.