Everything about ShizNat fanart kicks ass. First of all, it features Shizuru and Natsuki, two characters who are almost as cool as me. Then it throws in comical victimization; specifically, Shizuru victimizing Natsuki. Even the name ShizNat is brilliant. If you're too slow to pick up on the derivation, ShizNat comes from the "Shiz" in Shizuru and the "Nat" in Natsuki.
I respect ShizNat artists too much to steal from their websites, so I'm posting this crappy ShizNat that I drew when I was bored in my econometrics class:
As you saw in my crappy sketch, ShizNat fanart doesn't have to limit itself to Shizuru and Natsuki. You could always have Haruka getting pissed off at Shizuru while Yukino tries desperately to calm her down. Another popular variation has Nao victimizing Natsuki until Shizuru enters and victimizes both of them. As long as the chain of victimization begins with Shizuru and ends with Natsuki, it's 100% ShizNat.
As I mentioned earlier, some websites are loaded with incredible ShizNat fanart. Here's a
directory
that covers some of the popular ones.
My favorite is Jango-Joe's deviantART page. Be sure to check
out her scraps section. Here's another
pretty good directory.
UPDATE: I'm expanding the definition of ShizNat fanart to include art that features only Shizuru under the following
conditions:
1. She's doing something you wouldn't expect from her until episode 22
2. Natsuki is her intended audience (and therefore technically still ShizNat)
UPDATE #2: I just found out what that whole green onion thing is all about. Holy shit...