Once my co-lead and I figured out what sort of game we wanted to develop, I immediately got started gathering references from Pinterest. When reference hunting, I knew I wanted to create this really fun, misty, and thick jungle environment with old temple ruins and strange alien creatures. Eventually I found a nice list of images that really helped display that style of environment that I was looking for. 

After I found my references, I went into Photoshop and created a very rough top/down concept image. This helped me: get a general layout of the level, identify the different zones that the player will encounter, and different points of interest spots.