Well, when the AAA ABer was working, I just transferred NP to my side. Set up a junk trade, put something like "NP trade from main to side" in the wish list and went along that way. The account is clearly marked as a side account as well.
For my shell account, I just gifted things (nothing huge mind you, some SLM pieces). I have conversations with that account on my main to make it seem like we're actually sisters (I have my shell as my "sisters" account, so it looks less suspicious that it's on the same IP as my main , and I've made the account look legit. (nice lookup, painted pet, a couple of avatars and trophies). I've had that account gift me codestones I needed for training, when I actually played KQ, and used that account to always make sure my main won.
I don't actually have a sister. I have a shop on that account as well, so I've ABed on it, just using a proxy to be safe.
Haven't been frozen yet for it.