I'm visiting Moscow in Russia and have hired a couple of tour guides. I speak limited Russian - my question is do I address them formally (Vi) or informally (Ti)? Both are about my age (in 30s). Additionally, if they refer to me formally, how can I ask them to be informal. Is it customary to wait for a certain time before switching to informal grammar? Lastly - is there anything tour guides appreciate besides tips? :)
