03/23/2019: I may not be Vincent Vangogh or anything, but I like to learn from some of my favorite artists on youtube.
Kuzomari, MikeyMegaMega and Markrilly are some of favorite manga artists to study from. For american comic, I usually look at TheBoxOfficeArtist or VZA for American comic book styles since their art is crazy detailed and focused.
On a personal note of how I am trying to evolve, I follow Xa-xa-xa for their Wakfu art on deviant art, Bleach for simple, but defined, black and white detail and the Teen Titans cartoon style with a bit of Soul Eater.
Two other artists I follow are Baylee Jae and Jazza. Those two are fun and cartoony, with experimental styles I can enjoy. Makes me just wanna break out and test my skills.
I recommend all of these artists for anyone just trying to get better