4K downsampled
Hmmm. I need some texture mods. Anybody know the best option?
There are several. The ones which have the biggest impact are the Vivid Fallout mods, the high resolution texture packs from Valius (and get the additional one with the normal maps!), the grasslands mod, the springtime trees mod.
Use an ENB. Get the ENB dlls from the ENB website and then choose one which fits your tastes. I use the Olympus ENB as it has the best DoF and nice LUT based tonemapping (so you can switch in the ENB gui between the tonemapping by picking a different LUT picture)
For screenshots, use the console:
https://www.reddit.com/r/fo4/comments/3vfisr/fallout_4_console_commands_for_taking_photos/
(no more pesky huds, freecam, timestop etc.

)
I see you're still running 4K. That won't last, sadly. I'm using an i7 and a 1070, 32GB of ram, but it tanks to < 20fps in some cities (not even godrays at ultra), @ 1920x1200.