Done on Photoshop 6 in about 4 hours on a scanned in photo. The photo is of a sunset I took in New York City (it came back looking like that with the inverted V lights). I thought it would look interesting with something in the sky, so I made a rough sketch of an alicorn and dragon in Photoshop with a pen tablet and just layered the bodies over top of it then added a yellow lens flare. I think this one turned out okay, but the proportions (which are off quite a bit) would have turned out better if I would have spent more time trying to fix them.
Done with Photoshop 6.0, photograph, and Wacom pen tablet.