Thanks for asking, but Vijaya Lakshmi already described a very good method to blend two images (although I'd just leave out the selecting in step 2 and just use the Gradient Blend right away).

It's not so much that you blend two images as if they're in a kind of mixer. It's the sophisticated Layer Mask of the upper image layer, revealing parts of the lower image, that's creating this cleverly blended appearance.

And of course it requires the careful selection of a pair of candidate images to make it work that way. The perspective (viewing angle) needs to be aligned, and the key light direction needs to be similar. Scale, overall exposure, and color balance can be tweaked.

Oorspronkelijk geplaatst op Quora: How do I blend two images seamlessly in Photoshop?"