You can just sit there among a group and wait for people to come to you, but that is not effective networking. You have to take responsibility to strike up a conversation. If you feel intimidated or fear rejection, approach the person as if they want to meet you and they are waiting for you to take the first step. Remember to keep it positive and focus on the other person instead of yourself. This habit applies to all group functions whether it is a dinner social event, party or standing in line at the grocery store. Practice and improve your networking skills.