What cultural faux pas should I try to avoid making in Russia?

"It is important to be aware of cultural differences when visiting Russia. It is important to be respectful of the Russian culture and to avoid making any offensive or inappropriate comments. It is also important to dress modestly and to avoid public displays of affection. It is also important to be aware of the Russian customs and to avoid discussing politics or religion in public. Additionally, it is important to be aware of the Russian etiquette and to avoid being too loud or boisterous in public. Finally, it is important to be aware of the Russian language and to avoid speaking English in public unless it is absolutely necessary," said another expat in Russia.