it's all about resources
the more props you have at your disposal, the better. It's not as intimidating as it seems regardless, with Norpo's ground props you can make terrain, with Witcher 2 rocks you can make good boulders for your landscape, with Skyrim props you can make distant mountains, then you can hunt for some nice foliage packs for grass and trees and etc.
gm_black allows you to set up your own lighting too. There's a few good tutorials on facepunch for lighting and making shadows look sharp.
Once you become a scenebuilder you never go back to maps. It's 5001% more dynamic and allows you to create just about anything you want within the limits of your resources