There are a few ways that I constantly strive for inbox zero. I hope that you may find some of these useful in your battle of the inbox.
I have multiple labels set up. Effectively everything coming in gets a label before I see it. This means that anything without a label is something I really need to pay attention to. Non-label is the unique email. But you might say, Jacob, that is rather arduous. But alas, I say, this is a function built perfect for a computer. So I....
When an email comes in, we want to label it. Email filters can automatically apply labels. Set this up for the ongoing emails such as bills or relatives or friends. My favorite suggestion is to filter on the keyword "unsubscribe" to automatically apply a newsletter label.
Most of my filters are based on a filter applied to the "From:" email address. The trick here is to include asterisks to cover multiple emails from the same company, e.g. "@jacobbolda.com" would cover essentially any email address format sent from my email domain.
The last advanced filtering technique I want to touch on is filtering on the "To:" email address. Surprised? This should always be the same, right? Well actually.... Gmail will ignore any periods in an address. Myemail@gmail.com and email@example.com, and even firstname.lastname@example.org all arrive at the same mailbox.
Along those lines, it will also deals with a + in a special manner. It will not consider anything after the plus as part of the address. So email@example.com will arrive at that same inbox. When you sign up for that kayaking email list, you can use firstname.lastname@example.org to sign up. Now you can filter all those seven kayaking email lists you signed up for into a "kayak" label. Set the filter using your special "To:" address. Magic! This has the added benefit of sussing out when a mailing list sells your email address as it is unique to each list. However, the clever ones will likely remove the + text.
There may be a good chance that if you are reading this, you have trained your Google fu well. If this sounds like crazy talk, do not fret! Google fu is not a requirement. There are two very useful functions when using the search in Gmail (and this works in Google as well).
The first useful function is making use of double quotes. A normal search will search for each word typed into the box separately. If you would like to search for a phrase, surround it in quotes: "kayak rental" promo code. After an initial search without decent results, I will typically narrow my search down with phrases.
The next level of searching is using a dash (aka a minus). You can use a dash to exclude certain words from your messages. Do you definitely not want to return results from Dan's Sporting Goods? Then add that dash to your query: "kayak rental" promo code -dan's.
The search can get real deep really fast. There isn't the best wildcard searching, but with clever use of all our new found labeling and email address fanciness, we can narrow down the results quickly. If you need a very specific set of emails, check out the Gmail Search support page for more options.
Have any other tips or tricks I missed that are worth sharing? Shoot me an email or tweet me on Twitterverse.