* Uninstall twitter, facebook and other social apps from your phone; only use the computer (or other device that's not constantly in your pocket).
* Even on your computer, log out of twitter, facebook and others. Only log in when you want to look into something (eg. check the social events, send a message), and use private/incognito mode for this; use 2FA - besides being good security practice, it's an extra hurdle so you won't default to "quickly check" the sites when your mental energy is low.
* When you do use tw/fb/..., unfollow/block/opt out of all the meme/cute/funny stuff (at least n my fb feed, there's basically 10 sites that'd constantly crop up - blocking posts by all of these greatly increased Signal/Noise ratio on FB);
* Have a reading list ready. I use iBooks on my iPhone to load up interesting articles, but you can use whichever method you prefer. The goal is to have something interesting/worthwhile to read available for the moments when you do want to look at your phone and/or kill some time (eg when in a long queue or waiting for a train). This something shouldn't require special focus or mental energy/capacity.
* Develop heuristics to ignore content that you know is junk but that tends to drag you in. I suspect this is slightly different for anyone, mine is: anything cute, funny, outrageous, sad or is a list of things. I am aware this potentially cuts out some genuinely worthwhile stuff and I'm okay with it. Considering my attention & time is finite and the Internet is (for all purposes) not, I'd rather have false positives than false negatives.
* I also have a high bar for what's newsworthy for me: anything that personally affects me (meaning I have to change my intentions or react in some way), and stuff that'll still be considered newsworthy in a month. Anything else gets ignored, no matter the medium. Again I'm okay with false positives. Also, since my friends are colleagues typically don't have the same approach, if I miss anything important (or really interesting), I'll probably hear it on the grapevine.
Couldn't be happier.