I have a temp folder where I put things I may need to refer to once or twice then delete, this folder keeps things I need shortly out of my inbox and the folder can be emptied without even having to sort through it

I also have a folder called confirmation/receipts where I put exactly that, confirmations that I may need to get one day, like confimation that i paid AT&T on July. 12, 2009

Another folder is the Important folder where I save things that are presumably important. 

Lastly is the Archived folder where I archive everything else I want to save but don’t want to save on my inbox. 

Of these, the Archive, Temp and the Filters are my most important tools in conjunction with unsubscribing from things indont read and not kidding my self about things I can do without reading. Setting up a system is more important than actually slaving once every year or two to clean your inbox only to get hundreds or thousands of items again.