1) Don`t drink tap water, it`s good only for teeth cleaning 2) Never buy anything in kiosks like Shaurma (Doner-kebab) and Belyashi (round fried meat pies) - anything made with meat, especially near railway stations and in outskirts. You run risk to get an intestinal disease. Better go to Subway, Moo-Moo cafe or something of this sort. 3) Don`t drink and drive :) Be careful on the roads, drivers here are not very amiable :( 4)  If you travel alone, take care of your luggage. If you are on a deserted street don`t show you`ve got something precious, abstain of speaking on your mobile phone. People called «Gopniki» (similar to «Chavs») usually choose a solitary careless passer-by as a victim :) 5) Traffic jams… Huge, giant traffic jams… Take an interesting book and relax =)