Magnus, you can apply it, even to your pants... but layering one image on top of another is very easy... the simplest way is to lasso the area and then move it with the magic wand. This is for placing one piece on top of another. If you want to place an entire image, there are three modes... Transparent, opaque... and another one. They are located at the bottom of the toolbar, I think... but I'm not sure. I mostly work with the lasso tool and individual pieces. I haven't needed to use entire images yet. By the way, there are plenty of tutorials on this topic online... but I'm self-taught.