Techniques excerpted from Lifehacker

1. Hold your breath longer.
   

   “Before you dive, take several short breaths first — essentially, hyperventilate. When you’re underwater, it’s not a lack of oxygen that makes you desperate for a breath; it’s the buildup of carbon dioxide, which makes your blood acidic, which signals your brain that somethin’ ain’t right. “When you hyperventilate, the influx of oxygen lowers blood acidity,” says Jonathan Armbruster, Ph.D., an associate professor of biology at Auburn University. “This tricks your brain into thinking it has more oxygen.”" (Source: Men’s Health)

2. Cure warts with duct tape.
   

   Forget about soaking your skin with harsh acids. “Put duct tape on the wart and leave it there for a full week. After 7 days, soak the foot in soapy water, then bandage the wart with new tape. It should take one month to shrink to half-size; in two months, it will be completely gone.”

3. Stop brain freeze with your tongue.
   

   “Press your tongue flat against the roof of your mouth, covering as much as you can. “Since the nerves in the roof of your mouth get extremely cold, your body thinks your brain is freezing, too,” says [Ben Abo, an emergency medical- services specialist at the University of Pittsburgh.] “In compensating, it overheats, causing an ice-cream headache.” The more pressure you apply to the roof of your mouth, the faster your headache will subside.” (Source: Men’s Health)

4. Scratch your leg to relieve your bladder.
   

   “If you scratch or rub the back of your calf for a few moments, really vigorously, you may interrupt the message from your bladder to your brain just long enough for you to make it to the toilet,” [continence expert Janetta] Webb said.” Or think about sex. (Source: Sydney Morning Herald)

5. Really use your ears.
   

   Your left ear and right ear have different specialties. “If you’re stuck chatting up a mumbler at a cocktail party, lean in with your right ear. It’s better than your left at following the rapid rhythms of speech, according to researchers at the UCLA David Geffen School of Medicine. If, on the other hand, you’re trying to identify that song playing softly in the elevator, turn your left ear toward the sound. The left ear is better at picking up music tones.” (Source: Men’s Health)

6. Free your mind under a high ceiling.
   

   Your brain will do better on creative work in a room with high ceilings. New research shows that people tend to think more freely and abstractly in rooms with higher ceilings, and tend toward more detail-oriented specifics in more confined rooms with lower ceilings. Obviously church architects have known this for centuries.

7. Think while you sleep.
   

   Studies show that people given a mathematical problem before they went to bed had higher chances of solving it the next morning. Also, if you’re studying for a test or preparing for a presentation, review the material right before you turn off the lights. “Since most memory consolidation happens during sleep, anything you read right before bed is more likely to be encoded as long-term memory,” says Men’s Health.

8. Cure hiccups with water.
   

   Grab a glass of water, hold your breath, and take 10 consecutive sips, without letting any air into your mouth while you drink. The hiccups will be gone.

9. Whistle with two fingers.
   

   “The easiest two-fingered loud whistle to do is to use the index finger and thumb. Here’s how to do it:

   Loosely touch the tip of your bent index finger to the tip of your thumb.

   Rest the bottom of your joined fingers (if you’re using your right hand, the thumb is to the right) on your lower teeth with the tips of your loosely joined fingers pushing against the bottom part of your tongue (which pushes back).

   Your lips should be pressed down against your fingers. The joined fingers make the “V” into which you blow (you should blow slightly down). It definitely makes a shrill sound that gets louder as you blow harder. Of course, this method works best if your nails are short.”(Source: Google Answers)

10. Tell if someone is lying.
        

    When someone’s lying, the length of his nose doesn’t change - but often speech pitch and rate do, as does eye contact, the number of “um”’s and “ah”’s he utters, and shifts in body position and nervous twitches. And crossed arms indicate self-protection or resistance to the issue at hand. Of course, in order to notice a change, you need a baseline. So you must first watch the person when talking about innocuous issues. (Source: Monster)

    Here’s a list of suspicious behaviors to watch for when someone may be lying:

    • A change in the voice’s pitch.
    • A change in the rate of speech.
    • A statement with a contraction is more likely to be truthful: “ I didn’t do it” instead of “I did not do it”
    • A sudden increase in the number of “ums” and “ahs.”
    • A change in eye contact. Normally, one makes eye contact one-quarter to one-half of the time. If suddenly, at the convenient moment to lie, he’s staring at you or looking away, beware.
    • Turning his body away from you, even if just slightly.
    • Placing objects (book, coffee cup, etc.) between themselves and you.
    • Suddenly being able to see the white on the top and bottom of a person’s eyes, not just the sides.
    • A hand reaching, even if momentarily, to cover part of the face, especially the mouth. A liar is not likely to touch his chest/heart with an open hand.
    • Nervous movement of feet or legs.
    • Mixed signals. Look for mismatches between words and body language. When someone’s telling the truth, her words, her face and her body language are all congruent. For example, if a person is honestly saying that she likes you, her face is usually relaxed, offering a gentle smile and warm eyes. Her body is calm and open. But when she’s lying, something is usually inconsistent.
    • Liars can muster a smile, but it doesn’t look natural. Even better liars can put on a convincing smile, but their eyes aren’t smiling. Still better liars can control their entire face, but their bodies seem closed or cold.
    • A guilty person gets defensive. An innocent person will often go on the offensive.

11. BONUS: Open Blocked Sinuses 
    Push gently at the point between your eyebrows and root of nose, its the point where the bone from forehead dips a bit to form the root of the nose. Now release and push the roof of your mouth with your tongue. This wiggling manipulation of a small bone in your nasal cavity will clear the nasal passages.     Continue this for about 20 seconds; your sinuses will drain in about a minute.