Flirting is a powerful thing, but the irony is that it works best when it's subtle - something natural, something you exude. It’s that often intangible little quality that makes a person attractive. The French encapsulate it with the phase "Je ne sais quoi," which translates, quite literally, as "I do not know what."

But I know what it is. The essence of flirting is to send a playful message and seek a response. It is an exchange. And it’s not just for meeting someone new. If you want a bond with your partner that is going to last, you should think of flirting as a tool you will use for a lifetime. Here are some tips on how to send a subtle message - with major impact.

Body Language Basics

Body language is a basic form of flirting. We use it so often when trying to meet someone new, but sometimes we get so comfortable in a long-term relationship that we forget the power of body language. If you want to work your technique on someone, try to become more conscious of your posture. Think about how you sit. If you turn your body toward someone, shoulders back, chin up and limbs uncrossed, you are inviting that person to draw near to you. If you cross your limbs and turn away, this is a message that you are not open to their thoughts, words or advances. Body language shouldn’t be exaggerated movements, just discreet little messages you project. All you have to do is become aware and open yourself up to them.

In a world where we are all constantly wired to electronics, eye contact can have an even a more profound effect. If you're in a relationship, turn the television and computers off. Set your phones aside. Look at each other and spend time together with no distractions. Eat food together or lie on your lawn and look at the stars for a few minutes.

If you are out to dinner, stack your phones on the table face down. And make the stakes high: The first person who cracks and starts texting has to give the other a massage. Or, better yet, the first person to touch their phone has to be the other's sexual slave for the rest of the evening. If you are addicted to your phone, this can be an exciting way to build anticipation. (And if you enjoy sex with a side of submission, maybe you just want to dive for that phone. Get some tips on this kind of sex play in A Beginner's Guide to Submission.)

Speaking of anticipation, another fun way to flirt while out to dinner might be to order your food and then excuse yourself to the restroom. While there, slip out of your panties. When you return to the table, (discreetly!) pass your panties to your partner under the table and watch the fun unfold! This is an explicit message that you want sex, but in a place where your lover is powerless to act upon it. The two of you will need to wait for your food, eat the food and pay for the check - all with this underlying excitement of what is to come!

Attend to Touch

Touch is another undeniable means of sending flirtatious signals, but subtlety is sexy here too. I am not talking about explicit touches. There are so many places to touch yourself or your partner that appear harmless to the outside world but send undeniable signals to your lover.

For example, when touching yourself you can twist strands of hair between your fingers; you can nonchalantly finger your lips; you can pet your own neck, right down to your collar bones.

And of course, you can touch and pet your lover too. Think about the parts of your lover’s body that no one gets to touch but you. These are their erogenous zones, and there are many you can touch in public, such as the inner arms, rib cage, thighs, neck and hair. The lightest touches in these regions will often generate amazing response. (Learn more about foreplay and a woman's erogenous zones in 9 Sex Moves to Rock Her World.)

A Little Goes a Long Way

Whether you're wooing a new lover or spicing things up with an old one, flirting can be a great way to send a subtle message - with major impact. Great relationships - and great sex - are all about learning to play. So invest a little time into making the sparks fly. Your partner will notice that je ne sais quoi ...

Like this article? Check out Ducky's book, "Sex With the Lights On: 200 Illuminating Sex Questions Answered.")