I use a handful of add-ons, but they are all directed at doing what you are doing: Increasing privacy and security whilst decreasing tracking. Even if you are aiming for the "bare-bones", I would still recommend uBlock Origin, HTTPS Everywhere and Privacy Badger.
Don't forget to add the WebRTC which can block your chat, voice, and video from monitoring and always use the private browsing of Firefox as it gives you more protection it can remove all traces of your browsing activity and it can protect you from keyloggers and block websites from tracking your PC.
If you completely have these tools in your browser you have 99% secured and no leaks for your privacy it is likely you are browsing anonymously except for IP.