There are a few good "un-frak your youtube" extensions as well. I've got mine set to disable autoplay, trending, chat, "related" at the end of video playback, and recommendations. Helps quite a bit.

Seconded. Here are the filters I use for blocking recommendations on YT, in case anyone else finds them useful:

    youtube.com##.ytp-suggestions
    youtube.com##.ytp-pause-overlay
    youtube.com##.videowall-endscreen
    youtube.com###related
    youtube.com##ytd-browse[page-subtype="home"]