[d4rti]

Consent-o-Matic [1] allows you to set your preferences once. I’d say it’s had about a 50-75% success rate. Sometimes takes a second or two.

1: https://addons.mozilla.org/en-GB/firefox/addon/consent-o-mat...

[BaudouinVH]

I'm using both these extensions - I don't see cookie consent very often.

[stjohnswarts]

this one works well for me also.