Well, that depends on the type of art. Woodcarvers just carved wherever they went, for instance. Painters would carry tools, rather than finished works.

Music and storytelling are good because you can carry the "finished work" in your head, to perform again and again.

Storytelling is probably the most different; here I tell a story once and people all around the world can read it. Storytelling in person lets you tailor the story to the readers--to the local dialect, or the age level of the listeners, for instance.