I've been making an army of Thousand Sons disguised as stone statues. I think there was a short story in the fluff that talked about them using this tactic as only a few members of their legion actually have to eat and stuff. Anyway, I've gotten most of my units build and painted and now I'm going to be building an Imperial Knight to be the centerpiece of this army.
So far I've been using a very quick and sloppy paint scheme to make all my units look like they were disguised as statues (painted like stone, with gold and red accents and then weathered heavily.) Many of my units have flock glued to them in places as moss and vines. (not pictured).
I'm probably going to start the Imperial Knight with the same treatment, but it's such a good looking kit that I want to add something extra to make it really stand out. Whatever it is that I add to the look could be done in smaller quantities on the other large units. My initial thought was some kind of glowing runes or heirogliphics, but that's why I'm here looking for ideas. It's a brainstorm, no bad ideas. Also here's some pictures of the models I have so far: