A tip I picked up ages ago to help cut down clutter and improve my personal time management - OHIO-FAT.
OHIO - stands for Only Handle It Once; and,
FAT - stands for File; Act; or, Trash
|Needs a little FAT effort|
So, OHIO means that when you pick up a paper (open a message) you should train yourself to decide and act on it immediatly. FAT helps to remember the possible actions. When you handle something (once) you should file it for reference, act upon it (e.g., pay a bill or reply to a message), or toss it into the trash. I've seen some people add Delegate to the FAT actions, but that ruins the acronym
Simple enought to remember - although among the time managmenet and organization crowd this is actually contentious.
For the pro side of the discussion, see the Karma Blog's post
Jennifer, at Sustainable Organizing explains that it's not quite that simple . . .