How do I manage my inbox?

I will soon start a new job where I expect to receive significantly more emails than I do currently. So far, I haven't had a system in place, except for marking emails as unread until I respond and occasionally using flags.

I would like to change that practice, now that I have a clean slate. But how do I start managing my inbox?

I use Mac Mail and would like to continue using it. I know how to set up rules and create smart mailboxes etc., but I can't really see the potential.

Thank you!