How to Organize Your Photos

For the past 3 years (since I had my first child), I have been struggling with ways to organize the thousands of photos (yes, really - thousands) that I have stored on my computer. Please tell me that you have this problem too. 
I have read countless posts on how to manage your digital photos and they have some great tips, like 'delete outtakes that aren't frame worthy or you know you'll never really use'. It's a fantastic suggestion; however, I can't do it. I can't bring myself to delete the silly outtakes of a kiddo photoshoot gone wrong. I feel like I would be deleting one of my kids… totally irrational, I know. I just can't do it.
So, all month, I have been transferring photos to Google Drive. It's my experimental solution to my current photo problem. You see, I have a MacBook Air and it appears that I have exceeded the data storage with all of the photos I have stored on here… I know this thanks to a little reminder message that pops up each time I try to load more pictures into iPhoto from my camera. 
Organizing All of your Photos Online
Now, I could go buy an external drive, but then I would have to keep track of that and transfer files again once I found a certain photo. Keep track of things is really not my thing. True story: I lost my wedding rings last week. Don't worry I found them… mysteriously hiding under my 3 year old's bed.
The best solution I found was Google Drive. I already use it to store documents and printables, so why not photos + there is an app for your phone too! Now I can access my photos wherever I am. You can also use Microsofts rebranded One Drive for this, but chose Google because I already use it so much. If I ever reach storage capacity with Google, I can always buy more storage. It would kind of stink, but it's worth it in my opinion.
With the location of where to store all of my photos decided, I am now trying to figure out how to organize the actual photos. I could organize them by occasion, by subject, by year… what is the best way... Maybe all of them?
The great thing about Google Drive and One Drive is that you can have folders within folders (a feature that I had always wished was available in iPhoto). So, currently I am organizing my photos by year / month and then occasion within each folder. Not hating the results so far.
How do you organize your massive amounts of photos? Any tips to better photo organization?