Do not leave luggage under supervision of strangers – having returned, you can not find neither luggage, nor the fellow traveller. Try not to doze - you can become a victim of swindlers, which only and wait for it to take away all: a bag, money, documents.
Do not exchange money to casual people – to you can vsuchit a forgery. Especially watch closely things at planting to a train – in turmoil it is possible not to be counted a bag or a suitcase.