Bring your local hosts a gift of pastries from a local bakery and expect your host to turn down the gift. This is common, but upon insistence your gift will be expected; if you are offered a gift, do the same and only accept after you host insists you take it. Expect your host to ask you to remove your shoes before entering their house and once inside make an effort to greet every person individually.
As the food is served, expect the host to serve the elders first and you, as a guest only second. Keep your hands within sight while dining and only begin after being told to do so or after you host signals the start of the meal. Enjoy your meal, but only use your right hand to eat.
Tipping in Azerbaijan is only common in Baku at nice restaurants; about 10% for sit down restaurants is common.
Drinks
Black tea is central to Azerbaijani culture and is probably the most widely drunk beverage in Azerbaijan. Two other common and fairly unique drinks are kvass, which is a fermented, but non-alcohol drink and sherbet, which is a naturally flavored drink, most commonly consisting of lemon, pomegranate, or other locally available flavors. Of course coffee, juices, soft drinks, and milk are also available.
As a primarily Muslim country, alcohol is not especially common, but Azerbaijan is fairly liberal so beer, vodka, and other drinks are available. Most of these beverages are imports as Azerbaijan produces few alcoholic beverages domestically.
The tap water in Azerbaijan is generally not safe to drink so it should be avoided.