If you're going to try to attract artists to work for you for free, the best thing to do is to start putting out good writing.
So try writing webnovels or fanfic, or make comics that either don't have drawn art, or have very simple art (look up things like Wondermark, Darths & Droids, Dinosaur Comics, Order of the Stick, xkcd and 8-bit theatre for inspiration), or even try making a simple story focused RPGmaker game or something, or make choose-your-own-adventure games in Twine.
...Basically, do things that will show that you're passionate about writing, you write clever stories, moving prose or witty jokes. That's what makes a partnership between an artist and a writer work; the writer provides value to the partnership by being at least as good as, if not better than the artist at writing, meaning that the artist can feel confident that what you make together would be better, and perhaps more likely to make money, than the artist's work alone, or at least that by having somebody to take care of all that story planning and writing is saving them time they can spend to increase their output of art.