How to add realism to your environment

This tutorial talks about a scene done in cinema4d, but most of the ideas can be used in any 3d program.  

For instance, he suggests using instances to save on memory.   He suggests to use 2k or lower images until the end of your project where you replace some of the ones that were closer to the camera with 4k images. Just to give you an idea the video he used, used a video card with 24 gigs of vram, and used almost all of that.  (So don't expect to make something of this quality with a laptop or desktop with only 4 or 8 gigs of vram.  You'll have to scale your project for what rig you have.   (further back parts require lower detail anyway because of level of detail)  He also talks about how he lit the scene, using only a handful of lights, and an equivalent emission shader on a plane.  His sun light added to much light so he used non reflective large plane objects that are black to add shadows in the scene.  (Like clouds)  You can use gobo's also.  (in the shape of clouds)   He talks about which elements he needed to show some sort of story of the character.  So his idea led him to add the certain objects in the scene that helped tell a story he had about a future war. i.e the mech, machine gun,  bullets.    He gathered references, and also used them to block out a composition.  Then he started replacing those images with his 3d set.  Overall a great video with a lot of tips.

Just noticed this was for a challenge.  These are very good inspiration of what makes a good shot.  (secondary motions, and details)