One easy step to increasing your brain function is to vary your daily routine and schedule. Oftentimes you will find yourself in a set schedule… You will do the same job, have the same activities, watch the same TV shows etc…
Adding some variety into your schedule, even small things, can make your brain work a little more.
For instance, you could take a backroad home from work that you’ve never driven before. You could go for a walk before/after dinner.
Try new things, challenge yourself and embrace new adventures!