Any tips or tricks to better looking enviroment?

I’m currently in UE 4.11 and I’m creating a level.
I understand that I can change Viewport resolution for editing and so fourth, but I’m referring to the actual in game graphics or resolution. I’m using high quality textures and materials and I’m going for a simplistic level, but I would like my environment to look amazing. I was wondering if maybe there were any tips or tricks to making your level look better using different textures, settings, meshes, materials that you might have learned along the way to give a game that extra oomph to look nice.

Just for clarification:
my issue isn’t my computers capability or the Viewport resolution settings.