How to free up your Google Drive storage quickly.

Well, I got a warning saying my quota has exceeded this morning. :(
I have 30GB Google Drive Storage plan.
My current capacity has moved up to 30.12GB!

According to the Google Drive Storage capacity pie chart summary [1], most space is consumed by my Gmail!

Now I wanted to find a way to quickly delete emails which are having large attachments.

BEFORE YOU ATTEMPT THIS MAKE SURE YOU HAVE BACKED UP NECESSARY EMAILS LOCALLY.

This is how to delete your email messages which are taking up more space on your google drive storage.

Type the following in gmail search box to search your Inbox for messages larger than a given size, say 10MB.
larger:10m

Then Select All messages by clicking the select all check box as shown below.

As you can see there are large number of messages in other pages, only 50 conversations are selected in this page.
Note that in my case, there is a link saying "Select all 36,603 conversations in Inbox"

Click on it to select all messages which are taking more than your mentioned space (10MB).

Now delete your messages by clicking on the trash bin icon.

Delete these messages from your Trash folder also [THIS WILL DELETE THESE MESSAGES FOREVER IN AN INSTANT, YOU CANNOT RESTORE THESE MESSAGES HEREAFTER FROM TRASH].

Now you can see that your used space has reduced [1].
Your space will be freed-up as follows. :)

After deleting messages taking up more space than 7 MB, my storage capacity summary as follows.

After deleting messages taking up more space than 5 MB, my storage capacity summary as follows.

[1] https://www.google.com/settings/storage