Here is the selection for the creative artist, art dealers, antique dealers, poets, and other art-themed roles: 

Dr. Bon's notes on the uninspired couch potato character roles:

Oh, this one is easy. There's a selection of yoga-joke Namastay on the Couch t-shirts and hoodies, which is a funny and easy costume for any unemployed, moocher, couch potato character.  Also, you can wear The Dude costumes, cat lady costumes, or just get a bathrobe and mess up your hair!

Pajamas are great - there's a selection of fun onesies above, as well.  Just remember that these characters don't do much besides stay at home, watch television, play video games and spy on neighbors.