Keeping eye contact will show how confident and attractive you are. whereas, maintaining less eye contact shows that you are nervous or you are lying
you must start a conversation by greeting them, with a good tone and with full of energy. By saying HI, HELLO OR NAMASKAR, Anything through which you want to start your conversation.
While talking to someone slightly lean forward Not much but little, this will show to the opposite person that you are interested in them and in their talk and also comfortable and open with them