How Does A Light Novel Get An Illustrator?

I promise this isn’t just filler, it’s a question that’s been bothering me and this seemed like the best place to reach for an answer.

Just how did VOFAN get attached to Bakemonogatari? http://gelbooru.com/index.php?page=post&s=list&tags=vofan

How does an illustrator get attached to a light novel? Do writers go to an artist before they try to get published, or do they meet artists through the publisher? Does the author pay the illustrator before publication, or do both the author and illustrator get paid by the publisher? And if the author does pay the illustrator beforehand, then does the illustrator make any money off of the publication? Is it usually a “professional” illustrator that works on a light novel, or someone the author found on pixiv and launched into stardom with the publication?

Besides my interest as a light novel fan, I’m also interested in this as a writer. I would really love to do some of my works in the style of light novels, so I want to know just how I should go about attaching an illustrator to my works.

Lighting in Bakemonogatari Episode 1: A Tribute to VOFAN?

Hey that looks kinda like...

When Bakemonogatari started, a lot of praise was given to the show’s spectacular background art, not so much because of the detail or style of the backgrounds, but because of the extensive lighting techniques. Some people have commented on the way that Bakemonogatari would not have been possible without modern technology, and many see it as a bridge into the future of what anime will look like. Of course, it being a SHAFT anime, most of the series doesn’t quite live up to the splendor of the first episode, but there’s something I feel the need to point out: I think there’s a good reason that this in particular was the show to use those new techniques on, and that reason was VOFAN.