I love combining photos. This one is composed of an avocado, a woman's face, and a bit of careful manipulation. The hardest part was getting a face (which is normally symmetrical) to blend with an avocado pit (not so much). Other than that, it's only a matter of adding shadows, warmth, and a little bit of texture to blend it all together.
I like to experiment. Sometimes that means combining photos and applying different blending modes, filters, and effects until I get a result that is interesting.