[scottLobster]

Also in my 30s, one thing I found that improved my focus/cognition more than I ever expected was strength training and exercise in general. I had never exercised regularly until a couple of years ago, and after two months of 2-3 times a week strength training with some cardio mixed in my brain felt like it was 20 again.

YMMV, but that and adequate sleep was what really did it for me. Also go easy on the alcohol, see if you can restrict it to once a week. Chronically imbibing even low amounts of depressants tends to, well, depress cognitive function. The enlightenment was driven by coffee and tea, not beer.