FF-config.txt

browser.cache.offline.enable - false | Disables websites from storing data on your computer for when you would be offline.
browser.newtabpage.activity-stream.feeds.telemetry - false | Disables Telemetry
browser.newtabpage.activity-stream.section.highlights.includePocket - false | Disables "Pocket"
browser.ping-centre.telemetry - false | Disables Telemetry
browser.safebrowsing.malware.enabled - false | Disables Google's malware monitoring.
browser.safebrowsing.phishing.enabled - false | Disables Google's phishing monitoring.
browser.safebrowsing.downloads.enabled - false | Disables Google's downloads monitoring.
browser.tabs.crashReporting.sendReport - false | Disables crash reporting.
devtools.onboarding.telemetry.logged - false | Disables Telemetry
dom.battery.enabled - false | Blocks sending battery level infoformation.
dom.event.clipboardevents.enabled - false | Websites won't know if you copy/paste.
dom.webnotifications.enabled - false | Disables embedded notifications.
extensions.pocket.enabled - false | Disables the proprietary Pocket service.
geo.enabled - false | Disables ff from sharing your location.
identity.fxaccounts.enabled - false | Disables any embedded Firefox accounts.
media.autoplay.default - 5 | Disables audio and video from playig automatically.
network.dns.disablePrefetch - true | Disables prefetching.
network.dns.disablePrefetchFromHTTPS - true | Disables prefetching.
network.http.sendRefererHeader - 0 | Disables referring website notifications.
network.prefetch-next - false | Disables prefetching.
network.ttr.mode - 2 | DNS-over-HTTPS (DoH)
pdfjs.enableScripting - false | Prevents some malicious PDF actions.
privacy.resistFingerprinting - true | Resists fingerprinting.
toolkit.telemetry.enabled - false | Disables Telemetry
toolkit.telemetry.server - (Delete URL) | Disables Telemetry
toolkit.telemetry.unified - false | Disables Telemetry
webgl.disabled - true | Disables some fingerprinting.

WebRTC

media.navigator.enabled - false
media.peerconnection.enabled - false | NEEDED FOR OMEGLE
media.peerconnection.turn.disable - false
media.peerconnection.use_document_iceservers - false
media.peerconnection.video.enabled - false