I also talk with new people while I was on the journey. But the discussion will be very general and exchange of opinions on general matters. Sometimes during the discussion, we may come across a common friend and this discussion may go on that person and our relationship with him etc. But it will not be in a particular aspect of any one of the two of us. Sometimes we will be talking about certain issues with an unknown person without knowing his view on that. That may hurt the other man. So we should be a little careful in such conversation.
Generally talking with strangers start with a common description of the weather or whispering a general complaint - how hot is today; train is so late; the society is deteriorating etc.
Depending upon the response of the stranger the talks will start. Some people are very reserved and they will not respond to these initiating clauses so there is no hope of further dialogues.
Most of the time what I found was that the stranger was starving for talking and will immediately respond as well try from his side that somehow the chit chat continues.
There are cases when strangers looted the gullible people so one has to be very careful in that respect before starting the ignition to talk.
Knowledge is power.
The first thought that we will get and we will ask them is, "what is your name?" Some questions would be, where they belong, this will help to find a connection with the native place if that coincidentally matches with yours.
It is not easy to talk normally, however, we will need to study and observe the mood of the person to interact. We will need to understand their actions and reactions. We should not open up to strangers completely because it is not easy to understand one's inner thoughts at the first meeting. So, we should be careful there.
Do what inspires you !!
In trains, buses or in waiting rooms, often the conversation starts with a few cautious tester questions. Based on the tone, body language and facial expressions we can gather that yes we will have a good conversation or we wouldn't have a chat. As long as the questions are generic and not get into personal details it is fine. I tend to slowly detach myself when the discussion gets personal, where do you work, which street you stay, how much do you earn, these are pointers that the person will not stop until we stop.