The shape of the glass is very important. To assist you in your discovery of all the wine aromas the glass should have a reasonably sized bowl that closes somewhat at the top. This shape is known as the tulip shape. The wider bowl and narrow neck will allow for the aromas to collect and remain above the wine for your appreciation of the wine's full bouquet. The extreme opposite of this type of glass is the martini glass or a champagne coup.
Most wine glasses have a stem.
It is best when you are tasting wines to either hold the glass by the stem or base. This is done for several reasons. Should you hold the glass by the bowl, you will leave finger prints and it will become hard to judge the colour and clarity of the wine. Lotions or hand creams always have their own distinct smell as well. Eyeing the wine Visual perception of the wine is very important.