Eye contact

Keeping in contact with your audience makes them able to trust your approach. They will feel that you have a genuine connection with them and that you actually care about their reactions. It will also allow your audience to engage in what ever you are talking about.
   One way to maintain eye contact is to move from one person to another at the appropriate time, that way you're not focused on one person but at the same time you're not just looking at the back of the room.