There’s one thing that’s absolutely guaranteed to piss people off. In fact, it’s a surefire way to alienate others and drive them away.

This is one thing within your control that’s absolutely certain to ruin a first impression.

Do you know what it is? It’s not arrogance. It’s not being loud or rude. It’s not even your ugly Hawaiian t-shirt.

It’s bad breath. Foul-smelling breath is universally accepted as a negative trait. Nobody enjoys interacting someone who doesn’t keep their breath smelling fresh.

Maybe you’ve kissed a girl who just took a shot of tequila. Maybe you’ve visited a doctor who ate an onion sandwich for lunch and didn’t brush his teeth. Or maybe you just know someone who seems to always have bad breath.

In any case, I’m sure you’ve experienced how awful it can be. You cringe and fight to keep your distance from anyone with bad breath, but usually it’s unavoidable. You probably leave with negative thoughts about that person, wishing they would just brush their teeth more often.

The question is, are YOU that person? Most people with bad breath are completely clueless. After all, everyone hates bad breath, so nobody purposefully avoids brushing their teeth.

No, generally speaking people with bad breath have absolutely no idea. The key for you is to employ a few different strategies to ensure that you’re NEVER that person with the awful-smelling breath.

To begin with, you need to know how to test your breath. If you’re heading into an important meeting or out on a first date, you need to know whether or not your breath smells like cat food.

To do so, there’s really only one surefire test. First, you need to thoroughly wash your hands. Once they’re dry, you need to lick the back of your hand. Yep, that’s right, you need to LICK your hand.

Once you’ve slobbered on it, take a big whiff of the back of your hand. If it smells a bit funky, then your breath probably smells a lot worse. If after a few sniffs you still can’t smell anything, then you’re probably in the clear. Once you’re finished this breath test you’ll probably want to wash your hands again….

Now that you know how to test for bad breath, how can you prevent it? There are a number of things you can do to prevent and cure oral odors.

First, and very obviously, you should be brushing your teeth at least twice daily. I recommend brushing your teeth any time you leave the house, because this is one of the most effective ways of refreshing your breath.

Perhaps a bit more surprising, flossing is also very important. The buildup of plaque between your teeth can contribute to the growth of foul-smelling bacteria, so regular flossing is actually a major part of keeping your breath smelling pleasant.

If you aren’t already doing so, cleaning your tongue is absolutely crucial. Open your mouth and take a look in the mirror: you’ll see a layer of white gunk at the back of your tongue. Some of this is natural, and to be expected. But you should regularly scrape some of this crap off your tongue to reduce bacteria buildup.

There are tongue scrapers you can buy at your local drug store (beside the toothbrushes, usually). Or, if you’re really cheap like me, you can use a kitchen spoon. Starting from the back, gently pull the white gunk forward and off your tongue. Rinse the spoon or tongue scraper after every use. Remember, be gentle and be careful not to go too far back (or you’ll gag over the sink – not pleasant).

Chewing gum is hardly the answer to bad breath, but it can provide some relief. If you know you have bad breath, then a piece of gum is your new best friend. In addition to masking some of the bad odors, gum also activates your saliva glands. Having saliva in your mouth is an important factor in reducing bad breath.

If you opt to chew gum, don’t be too obvious about it. Some people, particularly older people, find chewing gum to be rude. Keep your mouth closed and your smacking to a minimum.

Another way to ensure that your breath is always fresh is to stay hydrated. And I mean stay hydrated ALL the time. Drink at least 8 glasses of water a day, and don’t let your mouth get too dry. As I mentioned, lack of saliva is a cause of bad breath. That’s why you often wake up in the morning with foul breath, your mouth is dry and you’re dehydrated.

Last but certainly not least, be smart about what you eat. Think ahead. If you’re going to be in an important business meeting or going on a date, don’t order that super spicy dish! Stay away from beer (and pretty much all booze), coffee, chocolate, onions, and other spicy foods.

If avoiding these things (particularly coffee and booze) is impossible, then be prepared. Keep a toothbrush and toothpaste in your office drawer or you car. At the very least, gargle with water a few times and chew a piece of gum. This can at least hide the odor of your most recent latté.

Some of these tips are common sense, but you simply must follow them all if you want to avoid driving others away with your bad breath. After all, nasty breath is the single most effective way of ruining a first impression, or any interaction!