I’m not an artist, but I have more than a few friends who are, so I thought this might be a good thing to post.
I used to do freelance illustration and gd, this is sound advice.
No free work and get paid on signing the contract. Otherwise they will take ur shit and never pay you.
Never send anything in to be ‘chosen’ unless it’s a comp. If u send any work in they must pay you for it even if they decide they’re ‘not going to use it after all’.
If you are going to do free work (I’d never stop anyone working for free, I still do things that look fun for friends when I can, and can point to things I did that no-one paid me for as things that got me real work further down the line) own it, lock stock and barrel.