If you want to do an image, say just on the Swoosh on the side of the shoe, with the image layer selected you would hold down COMMAND (on Mac, i think its just ALT on PC) and click on the little image in your layers box of the swoosh layer (the thumbnail beside the layer title)
This should give you a selection on your image layer shaped like the Swoosh layer. Next choose SELECT>INVERSE and it will select all of the image layer that is NOT the swoosh, hit delete to get rid of it and then play with your blending properties and opacity.
If you want an image to be on multiple parts of the shoe (like on my Louis Vuitton ones) you do the same thing but with duplicates of the image layer (one for each section of the shoe you want the image on) and repeat those steps for each duplicate.