There is a step that you can take which will help if your Gmail /Google account is compromised and that is to give Google your mobile phone number so that a password reset code can be sent to your mobile phone if your account is compromised.
How do you do this?
Log onto your Google account , this can be done through your Gmail account
Go to the Accounts and Imports tab and scroll down to the bottom of the page and there is a Change Account settings section.
Click on Google Account Settings and you will go to your Google Account Page
After logging on , go to change password recovery options
You will then be on the "Recovering Your Password "page
This enables you to enter a mobile phone number which can be used so that you can receive a password reset code on your mobile phone
This makes it much harder for someone to take over your Google / Gmail account