Make 3D photography decoupage by layering photographs to give an image dimension. Take four to 10 pictures or prints of the same scene. Cut elements of each print and arrange the elements on top of each other to create volume. For instance, cut distant elements, such as mountains, and glue (using glue stick) this print on a blank piece of paper. Use card stock, which is heavy enough to hold the prints, as the background. Place the same cut-out of the mountain (from a second print) slightly beneath the first print and glue on to add a second layer. Create between four to 10 layers.
Prepare a decoupage paste, which is essentially watered down glue. Mix in a jar two tablespoons of water for every four ounces of glue. Stir with a coffee stirrer or wooden stick until the mixture is fully blended. If the paste is still thick, add another tablespoon of water to achieve a more liquid consistency.
Trace or draw by free hand different images onto decoupage sheets, which are simply thick sheets of paper durable enough to withstand gluing and assembly. Cut the images out of the decoupage sheets and arrange by layering different pieces on top of each other. Place the first layer on a blank piece of paper or whatever pattern you desire for the background. Use decoupage paste to attach papers. Insert small pieces of foam, ranging in thickness between an 1/8 inch and a 1/4 inch, between layers of paper to add depth.
Embellish paper decoupage, such as that created in step 3, by incorporating other arts and crafts bits and pieces to paper layers. For instance, glue beads, jewels, ribbons, coins or dried flowers to the image. Place and glue (with decoupage paste) these objects between different layers, rather than adding all to the outer layer, to mix with the paper shapes and create a blend of depth.