You should absolutely be the one to start conversations if you have something productive to say. Don't start a gossip session, but DO share your opinions and/or ideas on a project that you are working on. Don't wait for someone else to open up a line of communication before you jump in, or you may never get the chance (or courage) to be heard!
Also, by initiating conversations, you are showing your teams mates that you value and welcome communication. It will make them feel more comfortable approaching YOU the next time that they have something to say.