I made shapes with pen tool, and applied effects/gradients in photoshop, download psd to see every shapes, and check fx (gradient overlayer,inner shadow etc.) to see how it`s done. Everything it`s made from scratch i did`nt use images only Photoshop and what have default. I used in few places brush on a layer mask for more complex pieces to have a texture look. I used about 10 hamburgers pictures for inspiration but i did`nt traced, just looked on colors and how light and shadows look, what shape have, what texture, etc, and tried to find a way to imitate that.