Hope it’s useful to future me or anyone else.

Conflicting Intel Graphics Installer for Linux and NVIDIA proprietary drivers

Installing these Intel drivers will cause your system to not start X up. You can still install them, but then you need to do this:

sudo apt-get purge i915-4.0.4-3.19-dkms
sudo apt-get install --reinstall xserver-xorg-video-intel libgl1-mesa-glx libgl1-mesa-dri xserver-xorg-core
sudo dpkg-reconfigure xserver-xorg
sudo apt-get install --reinstall nvidia-355
sudo dpkg-reconfigure bbswitch-dkms
sudo ldconfig -n
sudo update-initramfs -u

sudo prime-select nvidia
sudo nvidia-xconfig

sudo reboot

And if for whatever reason Unity doesn’t start up anymore, then Right click on desktop, choose Open Terminal and run

dconf reset -f /org/compiz/
setsid unity

If screen goes black now, switch to some other VT (e.g Ctrl+Alt+F2), login and sudo reboot

Speaker doing pop noise when shutting down computer

Add to the end of /etc/modprobe.d/alsa-base.conf

options snd-hda-intel model=,generic

(yes, with the comma)

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=71511