Hand Study (needs to be updated)

Video game thumb:  as I was playing "mario Kart" on Nintendo 3DS, I noticed that there was a depression on my right thumb which I was using for the gas button. If you observe carefully in the picture, you can see the depression on the tip of my thumb.

Writing hand: usually when a person writes he/she can't do much to avoid getting pen marks on both their hands (but they will usually have more on the writing hand). This can tell you what hand does such person write with, it can indicate to a profession such as a student, a secretary and many others; but remember deduce shrewdly, don't let this be you're only evidence, try to sort it out using other evidence. As you can see in the picture this person writes with his right hand and  uses a black ink ball point pen (fountain pens leave thicker marks)

Smokers fingers: the tar from the smoke of a cigarette stains your fingers and nails (and teeth), and produce a yellow and in some extreme cases dark brownish color. But these can also be caused by some medications, a medical condition and regular use of nail polish.

Your Brain

"My mind," he said, "rebels at stagnation. Give me problems, give me work, give me the most abstruse cryptogram, or the most intricate analysis, and I am in my own proper atmosphere.
                      The Sign of Four by Sir Arthur Conan Doyle 
Your mind is like a engine, if you don't use it, it will rust the gears will get stuck and when you really need it, it doesn't work properly. This is what Holmes meant, even doe that doesn't mean that when your bored your going to do some cocaine, instead try buying a puzzle and when that gets boring get a harder one, keep your mind sharp. The Method is not for idiots. 

Everybody Lies

If you watch House M.D. you've probably heard this a lot, this is true, even our favorite presidents were liars. President George Washington known for his "good morals" really married his wife Martha (widow at the time) for political and economical interest, during the American revolution he was known for his mastery of espionage    and deceit. If you learn to accept this than you can deduce things by hard physical evidence instead of what people are saying.
The thing about lying is that there is no perfect way to fake it, for example: a person that is acting surprised (in a happy way) probably won't make a full smile or his eyes won't "smile" along with the rest of the face. Your brain is a natural body language seeker you jest have to ask it the right questions (truth or lie, real or faking, is he/she mad?, who is in the leader in the group?) but reading on the subject helps a great deal and I do recommend you to do so.

Examples of The Method in other sciences

To the ordinary eyes, the night sky is simply a moon and bunch of bright lights but to the trained observer, there are not jest stars up there he/she can look up and distinguish near planets, satellites and stars, without the help of a telescope or any other tool other than his eyes and brains. We may also look at a cloud and jest see a giant     piece of cotton however anyone in the field of geography can tell you there is a great significance in the shape witch allows us to tell the difference between a cumulonimbus (http://en.wikipedia.org/wiki/Cumulonimbus_cloud) and a stratus (http://en.wikipedia.org/wiki/Stratus_cloud)

Practice

Practice doesn't really make perfect but it does make you an expert, The Method is no exception, but it's a field science (if you can call it science) you have to go out and see, experiment, make mistakes and learn from them. Dr Joseph Bell(http://en.wikipedia.org/wiki/Dr_Joseph_Bell) often picked a person at random showed him into his classroom, show the man to his students, ask them to study him, and after they all failed to deduce anything, he would take a hard look at them and could tell different things ranging from recent activities, occupation, etc. You can also do this, just pick a public place (park, restaurant, street) and observe see what can you tell, and if you're sure ask the person if your right, but if your shy you can practice with friends and family members.