My photoshop works always use my own paper works, and I try not to take elaborated and with lots of colors photogtaphs to get the colors I want , (it's often with clouds and a common sky)
I try to gets effects with lots of filter and try a lot of manipulations with layers, I don't want the final effect to seem "a simple photoshop filter" or being recognizable to be made with photoshop
sorry for my bad english right now I've smoked some weed and drank too much coffee woh =p
ps: I often work them on photoshop while I'm naturally in a high mood or when I'm high with psych. So in the begining I make i make something I can gets good visuals when I'm in this state of mind, and after I try to work it out to something tha sober or lightly stoned people can look it and search for "things"
friendly;
Oliver