about:config settings to harden the Firefox browser. Privacy and performance enhancements.
You can use this settings in Tor browser too.
To change these settings type 'about:config' in the url bar.
Then search the setting you would like to change and modify the value. Some settings may break certain websites from functioning and
rendering normally. Some settings may also make firefox unstable.
Not all these changes are necessary and will be dependent upon your usage and hardware. Do some research on settings if you don't understand what they do. These settings are best combined with your standard privacy extensions