I'm looking for a technique/effect in Photoshop, whereby a picture or background can be masked/cropped within a shape layer, such that it will only appear within the shape area. For instance, I want a person's face to appear within a square and no where else.
Easy to do. Create a square shape. then place your image in the layer above the square. Next in the layers panel right click on the image layer and select "create Clipping mask" (I think that's the name anyway... certainly something with "clipping mask" in it). And you're done.