1.Become familiar with the traditional vessels.Sake is served in a small, usually ceramic flask called a tokkuri. It's usually bulbous with a narrow neck, but there are other types, such as katakuchi, which looks somewhat like a tea kettle.
2.Bring the sake to an appropriate temperature. Regular sake, honjozo-shu, and shunmai-shu are usually warmed to room temperature, while ginjo-shu and namazake (sake which has not been pasteurized) are chilled.  Do not heat sake above room temperature unless it is of poor quality.
3.Serve sake in each guest's cup, but not your own. Hold the tokkuri with both hands, palms facing down. You can wrap a napkin around the tokkuri to prevent sake from dripping down. Fill each guest's cup in turn. Don't fill your own. It's the guests' duty to ensure that the host's cup is full.
4.Hold the cup properly as it is served to you. In formal situations, you hold the cup up when you're being served. Wrap your hand (usually the right) around the cup with one hand and rest it on the palm of your other hand.