If you're using Google Apps, then I hope you are capitalizing on the fact that Google was a search engine FIRST! Did you know that there is a search bar in all of the core apps (Gmail, Drive, Calendar...)? While I train people all the time on creating folders in their Gmail inboxes and in their Google Drive, I myself do not always have time to stop and do this. My saving grace?! GOOGLE SEARCH BAR!
In my Gmail inbox I can search for a keyword or sender and Gmail will pull up not only email with those search terms, but also email attachments! (You can even do an advanced search by clicking the arrow on the rige side of the search bar!)
In my Google Drive, all I have to do is search for a word in the document (PDF's too!) and Drive will find it! In fact, when you start typing in words, Google Drive gives you options right away. It's too easy! It will even indicate if there is a file in your trash that matches your search criteria!
Google Calendar is no exception. Can't remember when that meeting was last month? Just search for it in the search bar on your Google Calendar and let Google do the rest! Genius! And all of this is ... wait for it ... FREE!
When your emails come in faster than you can organize and your Google Drive is jam packed ... don't fret! Google Search within apps can save you every time. Let Google work for YOU!