I wanna get into art college after high school to study animation and character design, and I guess as an artist myself, it really comes down to just taking your time. A large part of art IMHO relies on you having good observation and perception which is used to help translate what you see in real life or in your head down onto paper.
I like to think of artistic skill as some sort of knife or sword – you have to constantly sharpen it if you don't want it to dull. That means you need to practice whenever you can. I would say 'practice every day' but obviously not all of us have a lot of free time to do art so I just leave it at 'practice whenever you can'.
Some of my work in the spoiler:
Now, I'm far from being an expert in any sense of the word, but it's very important to not only take criticism and use it to improve, but also appreciate your work for what it is. You'll notice that in the third pic (the luchador), the anatomy particularly with the right arm looks asymmetrical and a bit weird, which is something that I didn't immediately see until I received criticism on it. Even so, I had a great time drawing it, and it's still something I take pride in currently.
I've noticed that in this thread that there have been people saying 'I wanna draw but i don't know what' or 'I'm never satisfied with my art. Just draw the first thing that comes to mind and experiment with different subjects until you find out what you like drawing. Scribble on the page if it helps you break through that mini-art block.
TL;DR:
• Find out what you're good at or what you like to draw.
• Take criticism on board no matter what.
• Practice whenever you can.
• Take pride in your work even if it has flaws.
• Don't let some stupid art block stop you from creating what you want.
Sorry for writing a goddamn novel in a forum thread, I just really like art.
And now, I leave you with a quote from Van Gogh.
"If you hear a voice within you say 'you cannot paint,' then by all means paint, and that voice will be silenced."