Rehearsing some safety measures (my opinion) should be taken when taking long journey:
*Do not take food from strangers.
*Do not share food with strangers.
*Do not keep water bottle outside.
*Do not use camera...
more... in front of guards.
*Use the most valuable bag of yours as pillow.
*When going to sleep at night, place your head at the outward direction, if not on side berth.
*Do not stand by the doors when the train is running.
*If you're drugged and you can feel that before losing your sense, handover your luggage to a descent- looking co- passengers/ family and tell them to call for help.
*Do not go outside or to toilet keeping your luggage open and unprotected.
*Do not keep your food in open.
*Keep your shoes under the seat.