To put it in tiltilltrlls' words; "After making the described changes, my game experience has been infinitely better. Buttery smooth 60 FPS. No micro stutter. Nice FOV. Life's good".
There are a couple of things you will have to do in order to improve overall Fallout 4's performance, like making changes in Fallout 4 Launcher Settings, Fallout4.ini, and Fallout4Prefs.ini changes. So let's get down with it.
The settings described below may or may not be the best possible settings for your rig and are subject to taste. Shadow Distance and Godrays Quality, are absolute FPS killers for most machines, so turn these down to Medium and Low respectively. You will notice a slight difference in image quality as far as shadows go, but it was well worth the ~15 frames.