The British, United States and Dutch governments have advised all their citizens to leave Russia immediately. This is following the mass censorship bill that the Russian government has passed which will allow its authorities to imprison people for up to 15 years if they “misreport” on the ongoing conflict in Ukraine.
While under peacetime conditions air travel would be the obvious route out of the country, the recent closure of airspaces, banning of airlines, and poor relations between immigration authorities have all caused this method to become a no-go.
Land crossings are the implied alternative, however there is considerable evidence to suggest that the Russian government is planning on implementing a state of emergency to limit the ability of westerners to leave the Russian border. So if you have no urgent reason to stay in the country or are already planning on leaving, time is of the essence.