Good shader's are a massive advantage
No clue about them though, beyond tweaking obvious stuff in existing ones. I consider them interesting but a bit above my attention span
I use Game guru because I want to avoid the low level stuff
I have Dark Shader. Never found it much use even in DB Pro. It's a wonder there aren't any decent packages out there that can make DX11 ones in a more art package style.
I do vaguely remember one have seen, Paint 3D I think, but no idea if it could be used for GG. Might be worth a look @smallg
SPECS: Ryzen 1700 CPU. Nvidia 970GTX. 16 Gig Memory. Win 10.