There is no unique way of becoming a good illustrator, cartoonist etc, and that's what makes it so exciting in my opinion. It's like this Jean-Claude Vandamme movie i liked as a kid, Bloodsport : fighters from around the world, some were very technical and learned very precise techniques while others were simple street fighters breaking bricks with their foreheads. In the end, everyone managed to kick ass. My point is, listen to advices but make sure you're still making progress in your own way. I have a few friends who learned things in a very chaotic and personal way and who are still excellent artists. Who knows how their work would look like if they had followed a more academic path ?
Don't get me wrong, i'm not saying "Screw traditional learning techniques", i just wanna say that, as you possibly can't follow every advice, be smart and be sure to take a personal approach when learning (that means you can totally think that my post is crap and choose to ignore it).
So my advice is :
DRAW. And when you're not drawing, think about drawing

It sounds like a joke, but basically art is just a brain thing so put your brain to work even if you're not holding a pencil, it'll help.