Just a quick correction here:
you get reputation for every season spent, not every piece made; otherwise any building artist would never become popular.
Now as mentioned by John, Benefactors are the better option, but there is a bit more to it to make it easier
Every time you get a Benefactor you get +3 xp; doing this takes a season, during this season you can host a feast or event to attract said benefactor so +1xp
so obviously you want to be finding as many benefactors as you can, so you want a high turn over of art, so taking Prolific Artist and being a poet is the way to go (Poets use Communication+Ability, doubles up for finding sponsors, takes little resources, and very little time); work out how many pieces you can crank out in a season and hunt down the appropriate amount of benefactors; you could argue that finding a benefactor or holding a "poetry reading" event does count as being diligent in your art from.
Now the trick to being a famous artist is actually being Bad at art; well to begin with. if you take Artistic reputation twice you need to create art of quality 12 or higher; which you can do with no ability (Communication 5 +5, Inspirational and Free Expression +6, Artes Liberalus 3 +1 = 12); further more you can further bonuses from improving your workshop as per Cities and Guilds, potentially up to +6. Being a Poet is a craft after all. Now this allows you to get the nice bonus reputation from rapidly rising in skill.
So you've got a high Communication, good social skills to wrangle benefactors, and Inspirational; So Agents, you can have a lot of them, dealing with people is basically your full time job already, and the moment they have a smidgen of loyalty to you they become near fanatics (loyalty being a personality trait after all). Now you can either have your Agents support your Poetry printer....I mean artistic talents, find new benefactors for you, eliminate competition, hype up your work; or your agents can be a series of benefactors who you just cycle out every year or so.
As with most art, presenting it while in a Magical Aura will help; as described on Pg 7 of Realms of Power: Magic, Magical Auras make things more vivid, clearer, superior. now mechanically this might not have an effect unless the aura is aligned to artistic talents, but its is far better then the drab Divine, distracting Faerie or demonic Infernal; plus if your art starts to produce Vis, you can get a whole bunch of new benefactors from strange, somewhat disturbing men or Magi as they like to be known.