[unabst]

Two techniques I use.

Batch Process by Elimination. Google labels/tags + rotating stars + quicklinks is a powerful combination. Quicklinks can search for tag and star combinations. Tags represent substance, and stars represent state. So these lists can be batch processed based on tag + star, with the initial combination automatically set with filters. It helps when you can control email aliases to filter by recipient also.

Minimizing Moving Parts. No threads + a preview pane eliminates back and forth, and when starring or unstarring, the list doesn't remove the message or change it's position, so your frame of reference stays constant. After a bunch of items have been processed, the list updates/shrinks by clicking on refresh or the same quicklink.

It took a while to arrive at this setup, but afterwards it's been impossible to move back to any classic email program. Just visually digesting a constantly changing long list of emails and folders is a lot of work. And that's before you've even gotten started.