Just as an image can say a thousand words, hand talkers are communicating far more than they know.

After studying famous TED talks, consultant Vanessa Van Edwards discovered that the ones that went viral featured speakers who used their hands the most. Indeed, an average of 272 hand gestures were used in the least-watched TED talks as compared to the average of 465 hand gestures in the top-ranked ones during the same length of time. 

"When really charismatic leaders use hand gestures, the brain is super happy," Edwards recently told the Washington Post. "Because it's getting two explanations in one, and the brain loves that."

So while talking with your hands is a good thing, it's also important that they're saying the right thing. Here are 11 rules of thumb to follow when using your hands during a presentation: 

1. Keep hand movements descriptive.

Though doing what comes naturally helps you avoid getting too choreographed with your gestures, having pre-planned descriptive gestures at the ready is also not a bad idea.

Indicate with your hands when you're talking about something big or small. Help audience members keep track of what you're saying by holding out one hand to describe the benefits of an issue and then the other to describe the downsides.

And when you say a number below five, show that with your hand to help people remember the number.  

2. Use open palm gestures to build the audience's trust.

Open palms indicate that you have nothing to hide. The gesture may have evolutionary underpinnings and it's one of the few universal recommendations made by speech coaches and body language experts. 

3. Keep your hands in the strike zone. 

The "strike zone" is a baseball reference that in presentations refers to the area from your shoulder to the top part of your hips. That's the natural area for you to gesture, so moving outside that zone can often be distracting. Though it's not a hard and fast rule, keep it in mind.

4. Don't point. 

Just don't do it. Pointing can appear aggressive and off-putting to many in a crowd.

5. Avoid the Clinton thumb. 

Politicians often do the "Clinton thumb," which is when you make a fist and rest your thumb on top. The idea behind it is to coach speakers out of pointing, pounding their fists or looking too aggressive. 

But just because everyone from John F. Kennedy to Bill Clinton has used it, doesn't mean you should. It just doesn't look natural for most of us. 

6. When you're at a loss, drop your hands to your sides. 

Dropping your hands serves as a reset button of sorts. When you've spent the last few minutes pointing or something just doesn't feel right with the gestures you're using, try this trick. But remember to only keep your hands at your sides temporarily. 

7. Avoid drawing attention to the wrong places. 

Clasping your hands in front of your groin area draws attention to the wrong place. And it keeps your hands still, which means you aren't using them in a more effective way. 

8. Conducting is for orchestras, not public speaking. 

Just as you would mix up the sentences you say, avoid repetitive gestures like slicing the air or chopping your hand into an open palm. Women in particular need to be careful about "conducting" because research has shown that female voices stimulate parts of the male brain used to decipher music. 

9. Keep objects out of your hands.

If you have an object in your hands during a presentation, you may unknowingly fiddle with it the entire time. Whether it's clicking a pen's top or rustling papers, all forms of fidgeting distract the listener or make the speaker come off as nervous. 

10. Show your hands. 

You may feel safer standing behind a big furniture piece, but gripping the top of the lectern and making low hidden gestures won't do you any good. Have your hands out and moving or at the very least resting on the lectern lightly. 

11. Avoid spider hands.

German Chancellor Angela Merkel has a trademark hand gesture, where she holds her hands in front of her midsection, fingertips and thumbs touching in a diamond shape with the fingers pointed down.

Do not follow her example. The "spider hands" appear tense, and there's a risk of unintended meaning. Keep in mind the shape you're making is similar to the sign language gesture for a part of the female anatomy. And that's the last thing you want to be indicating to an audience.