The Secret

Fresher breath with one quick tip? Brush your tongue.  

Like your skin, the tongue needs exfoliation. Dead cells and bacteria can build up to form a whitish-yellow coating on the surface of your tongue. A recent study found that this tongue coating accounts for 43% of oral malodor (a professional way to say bad breath). Removing the tongue coating reduces the amount of bacteria in your mouth—that means better breath. 

So Easy
Right before you finish brushing your teeth, brush all over your tongue. That's it. Overachievers can get at the roof of the mouth, too.

There is no good reason not to adopt this great oral hygiene habit, unless you want people to avoid talking with you. Then do the exact opposite. And eat Funyuns.

How to brush your tongue without gagging:

Take a big deep breath. As you exhale slowly through the nose, quickly brush down your tongue during the exhaling breath. Avoid hitting the back throat—that will surely make you gag. 

Data found in:
Van Tournout, M., Dadamo, J., Coucke, W. Tongue coating: Related Factors. Journal of Clinical Perio 40:180-185, 2013.