Step 1: SWIRL
If you're new to all of this, start by keeping the bottom of your wine glass on a flat surface. Doing this will help you maintain control and minimize the risk of flinging wine across your table. Hold the glass by the stem and swirl the wine into a funnel, spreading the liquid over the surface of the inside of the glass. You can swirl the wine in whichever direction feels most natural for you, but most right-handed people find that a counterclockwise motion is most comfortable, and lefties usually prefer to go clockwise. This act of swirling aerates the wine, which has not been exposed to oxygen since it was bottled, and it allows the aromas to begin to open up.
Step 2: SNIFF
Sticking your nose well into the glass and inhaling, as opposed to keeping your nose above the rim of the glass, will allow you to experience a full range of aromas. Some people like to leave their nose in the glass for a while, and others prefer to take short, deep inhalations. Mix it up and experiment. You're smelling to detect fruit aromas, fruit ripeness, organic material, inorganic material, oak, alcohol, and any potentially negative issues with the wine such as oxidation or aromas that indicate a "bad" cork.
Step 3: ANALYZE
Analyze the aroma further. Get more specific about the aromas you can identify. If you smell fruit, what kind of fruit? If you smell flowers, what kind of flowers? What do the different aromas remind you of? Our olfactory sense is linked closely to our memory. For instance, the oak aromas in Cabernet Sauvignon can sometimes smell reminiscent of dad's cigar box, or a little saline-like smell in a white wine can take you back to your favorite beach.
Keep smelling and keep an open mind. Does the wine have spice aromas; such as pepper, clove, anise, cinnamon, or vanilla? What about tea? Or possibly nuts? Consider cedar, oak, herbs, damp earth, chocolate, tobacco, char, smoke, tar, mushrooms, red meat, grass, hay, or asparagus. All of these notes, and many more, can be clues to the wine's origin, grape, and production methods. Try keeping a tasting journal to record your observations!
Step 4: SIP
Sip a small amount of wine and move it around your mouth so that all of your taste buds come in contact with it. From here, it's important that the aromas of the wine make their way to your olfactory epithelium, a specialized tissue inside the nasal cavity that is essential in smell. To help achieve this most effectively, some people pucker their lips and suck a small amount of air through the wine; others find it easier to "chew" the wine as if it were food, and some will do both to enhance their experience of the wine. Give it a try!
Step 5: COMPARE
How does the flavor of the wine compare to the things you smelled before sipping? Are some of the aromas/flavors more pronounced when you taste them? Did some aromas disappear entirely in the taste of the wine?
Step 5: FINISH
Note how long the majority of the wine’s flavors remain in your mouth after you've swallowed the wine, this duration of overall flavor is called length or finish. Some wines can have up to one minute of finish, or more, and a longer finish is often an indication of higher quality. Be aware of the alcohol level when assessing the finish of a wine; in a balanced wine the alcohol will barely be noticeable.
Step 6: REVISIT
You will be amazed at how much a wine changes when it is left exposed to oxygen for a short period of time. Pour a couple ounces into a glass and set it aside for an hour, then start the whole process again. What changes did you notice? Some wines that have a formidable tannic structure, contain a bit of unwanted CO2, or display slight off odors like H2S, benefit greatly from a little air. This is why we decant/aerate some wines!
After all of that - do you like the wine?! This is what it's all about after all -- you can analyze the fun out of anything, so don't overthink it! Enjoy the excitement of exploration and use this process to build your understanding of the wines you like to drink!