I don't have experience doing the Losers challenge, but AFAIK it would work like: an artist explains their project (via words, draft, or mostly finalized artwork), and 1 or more people make a team based on that project. So Mific might post sketches of the team as Snoopy characters (and say how she plans to make a comic), and a writer would go \o/ and write a complimentary WWI flying ace AU (and another team member might make plushies, etc.).

Creating primaries and complements would be the assignments, with regular check-ins and a definite deadline. - busaikko