What I've found so far is that it takes a while to get good results like something that looks like its own creation instead of an overlap of pictures. There's no exact way to do this. If you modify existing artwork it works well enough since the source is already somewhat divorced from reality but photos are difficult. When it works it's amazing though.
First, the paper I call "Neural Patches" (Li, January 2016) makes it possible to apply context-sensitive style, so you have more control how things map from one image to another. Second, we added extra annotations (which you can specify by hand or from a segmentation algorithm) that helps you control exactly how you want the styles to map. We call that "semantic style transfer" (Champandard, March 2016).
You're right about it being hard otherwise, it was for many months and that's what pushed this particular line of research! Try it and see ;-)
You may remember the "Mazda" brand of bulbs
https://en.wikipedia.org/wiki/Edison_and_Swan_Electric_Light...