I ban reddit during work. The only sites I allow myself to visit are the ones that are very slow to update or one or two such slow subreddits like r/math (while the rest of reddit stays banned). When I get an urge I simply go check them out, see nothing has changed since my last visit and go back to work. This gives my mind chance to cool off and regroup. After awhile this turns into a habit and you start visiting sites like reddit much less often.