Dominik Dammelhart of Curse Studios goes over some of the key points in creating a lush outdoor flora scene taking a look at some of the settings for the Shaders, render settings using VrayforC4D discussing some of the issues that he encountered with render-times and offering some helpful solutions to keep the rendering time down.
Dominik also lays out some key points to how he created all the plants and foliage in the landscape, showing how he was able to put grass, plants, leaves, etc. in the scene by creating render instances in a Cloner Object and V-Ray render proxies.
Dominik also provides the final scene file [direct link] that is available for download freely, so that you are able to pick apart and check out the Cinema 4D file for any answers to things that he did not cover in this overview.