While there is little doubt your host will be gracious, you must return the favor so bring a gift if dining at their residence. The Ukrainians make great cakes, which can be found in a number of stores and bringing a cake is the perfect gift, and almost expected in some areas as they may not have prepared dessert. If you plan ahead however, the best gift is a bottle of imported liquor, particularly from your home country. As you're expected to try everything, the Ukrainians gratefully welcome new liquors and cherish trying a new one.
Bread
Before entering their house, remove your shoes and wait to shake hands until after you have completely crossed the door's threshold. Once seated there are a couple drinking reminders to be aware of. Before drinking alcohol, especially vodka, wait for a toast; the host will lead this ceremony and will say "za zdorovya" (to your health) which is your sign to drink. Whatever you do, don't finish your glass or it will be a very long night. Just take a small sip and follow others when they grab some bread or a non-alcoholic drink to chase the hard liquor. As the alcohol starts to hit you, so will the personal questions. Asking about how much money you make or your personal relationships are common and expected so be ready to confess your secrets, but asking them the same question in return are also accepted as there is no double standard.
If you're in Ukraine for business, dining rules are fairly standard on European standards. Wait to be seated and until everyone is served before beginning. Eat with your knife in your right hand, fork in the left and keep your hands in sight at all times.
Tipping is not common in Ukraine and after experiencing the standard poor service nearly everywhere you won't be inclined to tip anyway. The only exception to this rule is in nice restaurants catered to foreigners, particularly in Kyiv. Service in these locations substantially improves and tips are expected in the form of about 10% for a meal.
Drinks
While Ukraine boasts all the popular non-alcoholic beverages, such as coffee, tea, juices, milk, and soft drinks, the most unique non-alcoholic drink in Ukraine is kompot, which is a liquid flavored by various pickled fruits. As it can be flavored with any number or variety of fruits each has a distinct flavor.
The Ukrainians enjoy drinking alcohol and, while beer and vodka are the most popular drinks, samohon, a home-made alcohol is also popular. This drink is often flavored with honey and chili, but be careful if you consume this though since it is unregulated and can be dangerous. Many of the same flavored vodkas are available commercially as are other population alcoholic drinks, including many international brands.
The tap water in Ukraine should not be consumed because in many places it is not safe.