Here are some tips to hopefully improve the efficiency of peoples use of e-mail. If you take the time to go through this, I promise that it will substantially improve the quality of your life, at least with respect to e-mail.

Labels
Labels are tags that can be assigned to messages.  These replace what was known as “folders” inside Microsoft outlook and many other mail clients.  The difference with Labels is that one can assign any number of labels to a particular message.

You can apply a label by selecting “Labels \/” from the top bar when your on a message, and either type in a new label, or type or click on an existing label.  If you’ve enabled keyboard shortcuts in the settings, you can also press “l” then start entering the name of a label and hit enter once the label you want is matched.

Labels can also be automatically applied by filter, which I will discuss later.

Archiving
Do you let your Physical inbox pile up with a thousand documents until it reaches the ceiling?  Then you shouldn’t do that with your Virtual Inbox either.  “Inbox Zero” is the principal that nothing should remain in your inbox after you have dealt with it.

The way the Gmail inbox works is that it is simply a label assigned to all incoming messages called “inbox”.   After this label is removed, the message will no longer appear in your inbox.   This is all the Archive button really does, it just removes the inbox label from a message.   The message is NOT deleted.

Archived messages can be viewed by either going to another label that was applied to the message, performing a search, or by going to “All Mail” which can be accessed from the left hand column by clicking the “XX more \/”  link (where XX depends on the number of Labels you have), then selecting “All Mail”.

Adopting inbox zero was my new years resolution, and I cannot overstate the joyous effect that the embracing it has had upon me.  Before that, I had 40,000 messages in my inbox, which were like a ton of bricks on my chest.  Clearing my inbox out was a giant relief.    I did not however have to individually archive each and every one of these messages with 40,000 clicks.   Here is the procedure for archiving a large amount of messages:

1.  Select a date before which you would like to archive all messages, enter before:YYYY-MM-DD  into the mail search, (for example before:2010-08-01)  and hit “Search Mail”
2.  Click “Select All”  (note: on the new gmail which isn’t on google apps, select all is gone, you just check the checkbox in the top button bar)
3.  Select all only selects the messages displayed on the page, click Select all conversations that match this search at the top of the message list to select the messages on all the pages
4.  Optionally you could assign a label to these messages before you archive them, such as “old stuff”
5.  Click “Archive” and *poof* your inbox is much cleaner

Now to utilize the inbox zero principles follow these simple rules:
1. Apply any labels appropriate for the message  (sped up by using the “l” keyboard shortcut)
2.  After reading and completed your response to a message, or if you do not need to respond to a message but the message still has some value, click “Archive”.   If you’ve enabled keyboards shortcuts, this can be done by pressing “e”.
3. If a message is junk that you don’t need to keep, then delete it.  If you’ve enabled keyboards shortcuts, this can be done by pressing “#”  (shift-3) The message will be moved to “deleted items” where it will be saved for 30 days, just in case.
4. The only reason you would ever want to not archive or delete a message is if you intend to follow up to that message at a later date

Filters
Based on criteria which you enter, filters can be setup to automatically apply labels or automatically archive messages (among other things).

For example,  Facebook sends out large volume of mail, and while I could stop facebook from sending these messages, I’d rather just have a Facebook label applied to them, then have them skip my inbox and be marked as read.  Then I still have them for reference, but they’ll never bother me by polluting my inbox.

To do this I followed the following procedure:
1.  Click “Create a filter”  in the top center of the Gmail window, right nexdt to the “Search the Web” button
2.  Enter a search criteria, for this example I enter the From: address as “facebookmail.com”
3.  Hit Next Step >> and messages that match the search criteria will be displayed.  If nothing comes up, go back and check your search criteria
4.  Choose your actions,  for this example I checked “Skip the Inbox (Archive it)”, “Mark as read”, and “Apply the label: Facebook”
5.  Next to the create filter button, check the box “Also apply filter to XXX conversations below.”
6.  Click Create filter, et voila!  No more annoying facebook e-mails in my inbox

Obviously there are a lot more that can be done with filters, but hopefully this is enough to get you started.    I probably have 30 something filters setup on my Gmail, which automatically keeps my inbox quite tidy.  For example, I have a “Shopping” label.   I have a filter setup that auto-archives, auto-marks as read, and auto-labels promotional messages coming from amazon, ebay, newegg, etc.   If I want to blow my money on the latest hot deals I can always go to the shopping label and they’ll be there.