I often get this very question: How did you get this good this fast?
Now as I consider myself not being as good as people tell me, even struggling quite often with being an artist in general.
I do know how to get better and how to reach it fast. I'm still growing as I go and it's the main thing that keeps me going.
You need to get into the right mindset and the rest will follow. With the rest I mean:
3. Positive energy.
4. The NEED to draw.
Seeing growth in your work gives you the courage to work harder. You know that feeling when you're just about done with an image
and feel like this image is better than your last one, that great feeling. Use it!
Do studies! Lots of them!! Make film shot studies, live object studies, master-painting studies. They will teach you a lot about composition, lighting, colors, shapes storytelling etc.
You will hardly notice that you are learning thing