My Garter Snake Set up

I think it looks natural and nice. I would get rid of the gravel in the water bowl(I think its gravel) maybe add another green plant near back middle of tank but thats not needed ofcourse its nice as is.
I say that only because it could use a splash of something in that area. The rock cave looks great.

whats the substrate

the substrate looks like cyprus mulsch which zoo med sells for terrariums,etc. It looks natural and great but you can buy way way more for less money in garden stores exact same thing.