If you're great at writing or art, you might be able to earn some money creating graphics and/or prose for greeting cards. This page has a huge list of 47 companies that are regularly seeking submissions from freelance writers and artists for the greeting cards they sell.
Check out this HUGE list of legitimate sites that pay you to work from home as a writer. There are gigs for writing blog posts, recipes, short stories, greeting cards, and much more! via The Work at Home Woman