For the most part, and with the exception of flavored vodkas, vodka has a mild, neutral, almost non-existent flavor, which is why it pairs so well in many mixed drinks. Poor-quality vodka has a slightly bitter, stinging flavor, almost reminiscent of rubbing alcohol.
In addition to being generally flavorless, vodka typically has a light odor that is either slightly grainy or sweet. Vodka should also be virtually colorless, although some vodkas, even high-quality ones, may have a yellow or blue tint to them. A good quality vodka goes down smooth and creamy and should not create a burning sensation on the drinker's palate.