in Saint Petersburg
Tipping in restaurants and hotels is not mandatory although it is often appreciated. There is no "set" level and is left entirely to your discretion.
Meanwhile City Guides and their drivers often expect tips, the guides generally get more than the drivers and prefer hard currency (US dollars or Euro) although money is money and roubles are welcome. Once again the amount is at your discretion and depends upon how much time you have spent with them and the type of tour you have taken.
NoteIf paying by cash in restaurants – saying
“thank you” at the moment the money is collected implies
that no change is required.