I would suggest thinking about the conversation from the other person's point of view when it comes to knowing what to say or what questions to ask.
Invest yourself into the conversation. When someone you're talking to you tells you something about their job say, rather than ask 'what does that involve?' ask something like 'so I guess that involves quite a lot of....' This type of conversation is easier for the other person you're speaking to as they don't have to think so hard to answer the questions.
Also try and recognise what subject make another person light up and smile,and want to talk more. If you decide to start a conversation about films, and that person isn't really into films and just gives brief answers or says little, move on and try and find something they want to talk about. I know this is not easy but just being aware of these types of things will help.
Listen to the words people use in any statement they make, and then make another statement that relates to one word they use. This is a very useful skill if you feel you're running out of things to say.
Hope that helps
