It has been quite a long time I've been thinking about creating a design with those very realistic shadows. This weekend I decided to give it a try. I started to think about what would be the best way, manually recreating that would be too much work. So I decided to try the 3D capabilities of Photoshop. It turned out to be the easiest and quickest way. The result was also very good.
Link to the tutorial: https://abduzeedo.com/dramatic-shadows-photoshop-cc