Cookies when you need them, not when others need them to track you - gets rid of a site's cookies as soon as you close its tabs. Detects and protects against trackers and zombie-/evercookies. Trustworthy services can be whitelisted.

addons.mozilla.org/e...g-cookies/

Self-Destructing Cookies is not just a cookie manager, it's a new cookie policy. Do you think that cookies should need a reason to persist in your cookie jar, i.e. you currently interacting with the site that set them? Would you prefer your cookie jar to be empty in its steady state, except for a few sites that you care about? Are you worried about unconventional tracking methods? Then give this add-on a try....