These are my recommended privacy add-ons for Firefox:
Cookie Autodelete
Cookie Autodelete — when a Firefox tab closes, any cookies not being used are automatically deleted thus preventing tracking. You can then add only the cookies you trust. Easily import and export your cookie whitelist. Add the sites you want to keep cookies for to the whitelist (permanently) or greylist (until browser restart)
Enable “Automatic Cleaning” in settings or “Auto-Clean” in popup. Watch those unused cookies disappear 🙂
AdGuard
AdGuard is a comprehensive advertisement and malware blocker. AdGuard blocks ads in all browser and Mac apps. There is also a browser extension. The browser extension requires AdGuard desktop app to function. Install AdGuard desktop app (for Mac or Windows) first and then use this extension to expand the app’s capabilities.
Firefox Multi-Account Containers
Firefox Multi-Account Containers separates browsing information (like cookies) into separate into containers. This increases security, and allows you to use the web with multiple identities simultaneously.
For example, you can sign into two different accounts on the same site — for example, you could sign in to work email and home email in two different Container tabs.
You could use a Container tab for signing in to a social network, and use a different tab for visiting online news sites, keeping your social identity separate from tracking scripts on news sites)
LocalCDN
LocalCDN emulates remote frameworks (e.g. jQuery, Bootstrap, AngularJS) and delivers them as local resource. Prevents unnecessary third-party requests to Google, StackPath, MaxCDN and others.
Canvas Blocker
CanvasBlocker prevents websites from using Javascript APIs for fingerprinting.