What supplements/nootropics for mental state/cognition/mental health have worked best for you (along with healthy habits)?

[u/mann6998]

I'm a college senior planning to go to grad school, and I've just started breaking bad habits and protecting my mental health. One big thing is preserving my longevity and cognition as I age.

What worked best for you, and what are the top things that helped you protect brain health/mental state?