Artists are not helper ...

Artists are not helper monkeys; they’re not in it to visualize 'your' story, because it stopped being 'your' story the moment you engaged in a collaborative medium. From here on in, it’s also the artist’s story, and if you’re working with an illustrator who’s any good at all, you as a writer have to tamp down any control-freak tendencies you suffer under and relax into the process.
 Mark Waid

Quotes from the same author

Super-heroes were created to represent the best in all of us. We should aspire to match their nobility, not their ability to shoot big chrome guns.
 Mark Waid
In the world of comics, Jack Kirby and Will Eisner may have been more influential artists, but Joe Kubert was its most influential man. Even if he were to be remembered solely for his body of illustration work, he’d still be one of the greats, but by opening the Kubert School in 1976, he was able to personally mentor and educate literally thousands of successful artists who owe their careers to his teachings.
 Mark Waid
In the long run, the quality of your work is all that matters. That is your only resumé. Be professional. Make sure your editor or publisher can always reach you. Do what's asked of you if your conscience can bear it. But know that, five years from now, as fans or prospective employers are looking over your published pages, no one will care that this story sucks because the publisher moved the deadline up or because the editor made you work an android cow into the story. All they will care about is what they see in front of them, and they will hold you responsible for it, no one else.
 Mark Waid
Each time I think I've made a connection with someone... once they find out what I can do, whether it's hours or days later, everything changes. Invariably they freak. They get retroactively paranoid, wondering what else Clark Kent is hiding from them.
 Mark Waid
Comics are expensive. Don’t make me resent the money I spend buying yours. Every single moment in your script must either move the story along or demonstrate something important about the characters — preferably both — and every panel that does neither is a sloppy waste of space.
 Mark Waid