Fillers:
Elements such as water, fire, thunder/lightning, smoke/clouds,moon, nightsky.
Detail fillers:
Blackbird (X-Mens jet)
Xavier Institute for Higher Learning / Xavier's School for Gifted Youngsters
Beasts eyes, or beasts glasses:
Emma frost, I like this full body shot of her, so either that or one with just her face or eyes.
I found this picture on http://windriderx23.deviantart.com/ - amazing artist, I really like this Emma Frost with the whole mind aura going on.
If im not using Gambit as one of the main characters, I would like to have something like this: