While called many things I like to call my process Zero Inbox. I attempt at all times to have no unread emails and it is a real challenge some days as I subscribe to a large number of mailing lists. My daily average is ~200 emails but some times it gets out of hand.
On Gmail I use:
as my go to screen. There was a time when you could save filters and other things via some lab tools but they kept on getting retired so I just us the is:unread filter to organize things.
This is not perfect. Checking the spam box for emails for false positives interrupts the flow and I have to go back to the filter. On good days I can stay in the filter all day.