Quick facts on Yum Cha (飲茶)!
Since Dim Sum is usually linked with the older tradition from yum cha (Chinese: 飲茶; literally: "drink tea"), below are some quick etiquette tips for you on Yum Cha.
1) It is customary to pour tea for others before filling one's own cup during a meal.
2) When pouring tea for people on one's left side, the right hand should be used to hold the teapot and vice versa.
3) A common custom among the Cantonese is to thank the person pouring the tea by tapping the bent index finger (if you are single), or by tapping both the index and middle finger (if you are married), which symbolises the gesture of bowing.*
*This custom is said to be analogous to the ritual of bowing to someone in appreciation. The origin of this gesture is described anecdotally: The Qianlong Emperor went to yum cha with his friends, outside the palace; not wanting to attract attention to himself, the Emperor was disguised. While at yum cha, the Emperor poured his companion some tea, which was a great honour. The companion, not wanting to give away the Emperor's identity in public by bowing, instead tapped his index and middle finger on the table as a sign of appreciation.