A good wine pleases the sense of sight, smell, taste and touch.
Hold the glass to the light.
The wine should be brilliantly clear. The depth of color is significant: you will learn by experience what it should be for each variety of wine.
Mixing oxygen into the wine by swirling it around in the glass will enable you to smell and taste it better.
Swirl the wine in the glass to release its fragrances. Sniff rather sharply to carry them to the nerve ends high in the nose.
The "aroma" is the odor of the grape, most noticeable in young wines. The "bouquet" is the complex odor developed by aging. With experience you will be able to distinguish between them. The "nose" of a good wine is never weak or insipid.
Take a sip and roll it in your mouth to reach all the taste bud areas.
Associate the taste with the variety you are tasting. The various components should harmonize, yet the effect should not be flat.
Roll the wine once more in your mouth.
Note the amount of astringency present and get the "feel" of the wine. Depending upon type, age and other factors, it should be light, moderate or heavy to the mouth's touch, but never cloying or thin.
A very important technique for anyone tasting more than a few wines and wanting to stay alert. Too much alcohol deadens the senses and impairs your ability to discern nuances and subtle differences. Much can be learned about the wine without actually swallowing it.
Take the time after each taste to recall the wine's specific features and file them in your taste memory. As they accumulate, your ability to evaluate wine will grow.