My favorite technique in Photoshop is cutting and pasting two or more images together. The artistic possibilities are endless. In this instance, I combined two costumed models from Venice, Italy with street art in downtown Los Angeles. To paste a subject seemingly behind an element in the background photo as I did here (the models are behind the bars), you have to select the area into which the subjects will be placed and then use the pulldown menu command: Edit > paste special > paste into. The image that you previous placed in the clipboard (with Edit > copy) is inserted into the selection. Once this is done, you can size the subject by using Edit > transform > scale.