I mentioned it in passing before, but would like to make it explicit:
Closing every browser tab at the end of the day has had an inordinate positive impact on performance.
Likewise, I often have 4 or 5 books open, and strive to close those, and project plans, which I also look to close.
Leaving stuff open and sitting around means you don't start the day with a blank canvas to work with. It's easy to get pulled into whatever was left lying around.
It also makes it easier to leave things that are almost complete "...to finish tomorrow." But at what rate are things finished tomorrow? ...not high enough, for many of us. Much better to finish and wrap up today, even if a little fatigued.
I'm not dogmatic about it, though. The entry on my end-of-day routine looks like this:
Close Tabs (or justify it):
So there's room to leave things open, if I explain why I'm doing it. But if the worthwhile reason to leave things open persists for 3-4 days or more, then I just pull the trigger and close them out.
Somehow, the particular information on a tab often seems important to leave open. But, once closed even if it seems relevant, how often do I regret doing so?
Not very often. Less than 1% of the time, I think -- a few times per month at most. And that's more than compensated by having the extra mental energy and cognitive bandwidth freed up.
Try it out. It felt awkward to me for a while; it took about two weeks before it started feeling normal and like not-such-a-big-deal. But even during the acclimation period, the gains were obvious. Definitely recommended.