I read your rules twice and couldn't find anything about not using Photoshop!
I took this photo on my flight to my exchange year in Australia some years ago. At college, I attended a photo class and this was where I did my first experiments with Photoshop:
Click on image to enlarge
Nice one. Of course you can edit as much as you want. Not sure if this one makes it, but it was worth a try! 😉