Create a profile using the profile manager
firefox -no-remote -profileManager
I have different profiles for different usages of Firefox, to keep them separate. Hopefully that increases my privacy a bit. For example I have separate profiles for general browsing, Twitter, WhatsApp, Facebook, Google Calendar and my bank website.
Launch Firefox with a profile with
firefox -no-remote -P "name_of_the_profile"
Set prefers colour scheme to dark
You can update the style used by Firefox by going to
about:configand adding a new property
ui.systemUsesDarkThemeof integer type with value
Make everything dark with https://github.com/SrKomodo/shadowfox-updater
Reduce Firefox’s memory consumption
uncheck Use recommended performance settingsLearn more
Content process limit -> 1