The TOR project has a fork of Firefox with lots of defaults changed to prevent user fingerprinting. They also provide patches back to Mozilla. The closest to a list of defaults to change I found is
One issue is that without using Tor Browser itself, any attempts to de-fingerprint your browser end up making an extremely unique fingerprint if anyone's looking hard enough.
https://www.torproject.org/projects/torbrowser/design/#Imple...