You swirl by holding the bottom of the stem between your thumb and fingers, resting your hand near or on the foot of the glass, and gently rotating the glass on the tabletop to expose the maximum surface area of the wine to air. Swirling is important because it allows the wine to breathe, and breathing helps to bring out the nuances of smell and taste. In many ways, smelling is the most important step in the wine tasting process. To smell a wine, lift the glass you have swirled, put your nose into the bowl of the glass and take a short, deep sniff. By the time you take your first sip, your enjoyment of the wine has already begun.
Aromas are individual, primary smells of the grapes and juice before fermentation occurs.
Aromas evolve into the complex smells that are described as bouquet. The bouquet is not a separate or distinct aroma but rather the result of aromas layered together and combined into a new, often richer smell. There's no special technique for taking a sip. In fact, a normal sip is ideal. You don't want too much in your mouth, because you want to be able to move the wine around.