Making of "Chaleur et paix" by Mohammed Khalil
Using regular techniques in Photoshop, I’ve ended up with this:

Other objects in the scene had Alpha Masks and Displacement Maps:

All plants are simply textured with a mask in opacity slot, to cut down on RAM usage.
Lighting
One emitter (Spotlight) was used to light up the scene.

As you can see, I have created some boxes to block the light in certain places, allowing for more shadows to cast. By turning the viewport to Spotlight, you can manage to see which parts of your scene are exposed to light:


You can find the settings of the Spotlight used in the scene below:


