Gonna acknowledge right off the bat that this is just a drop in the bucket for amazing Steven Universe fan art. SU is like metaphorical catnip (which is metaphorical crack cocaine) for the tumblr community, especially since they started dropping week long "Steven Bombs" that leave fans reeling with each new revelation (spoilers below). Each episode is infused with expansive lore and populated with one of the most diverse casts of characters ever seen on a mainstream animated show. Any series that inspires this much love in all these creative people has to be doing something right.
If there's a particular piece you like don't be shy about clicking the artist's name, follow their blogs and maybe even buy prints or a commission.