Etiquette
It is polite to offer a small gift as a sign of respect when you are invited to someone's home. However, when given a present, the majority will ultimately object. If you respond that it's just a little something and then re-offer the present, it should be generally accepted.
If you anticipate having a less formal evening, it makes sense to bring some booze. Many Russian men believe that you can never have too much booze for a pleasant night, and in the end, they are proven to be entirely correct!
If you bring flowers, avoid giving yellow ones; in Russia, this color is associated with infidelity and estrangement, and it is especially forbidden to use it for bridal bouquets. The second superstition has to do with the quantity of flowers.
This number, which is 3,5, 7, and so forth, must always be odd. Flowers are always brought to funerals in an even number. Take off your outdoor shoes before entering a home. They might give you slippers to wear. Do not leave the table until you are invited to do so when dining with hosts. This is not regarded as courteous.
You'll be urged to eat more often than not. If so, consider it a sign of respect. And if you keep eating, they'll love you very, really much. Other Russians may share your meal if you're traveling by train. This is seen as exceedingly polite.