As Ellen Jackson said, success as a writer or illustrator depends depends more on intelligent persistence than raw talent.
Excerpt from Ellen's excellent advice:
"By 'intelligent persistence' I mean the ability to learn from mistakes, to figure out what you’re doing wrong, and then to change it. I know a talented writer who gave up after one rejection from one editor. I know another writer–with very little natural writing ability--who writes and rewrites and gets rejected over and over. The first writer has never been published. The second writer has published more than thirty children’s books. As James Michener said: 'Character consists of what you do on the third or fourth tries.'"