The Bollard has published some “drinking tips for sober people“.
Once the people you’re with are properly oiled, they won’t be as shy about approaching you. Common topics include sports, politics and, most commonly, themselves. Try not to be overwhelmed with details. Focus on the topic at hand and the person’s name (e.g. capitalism, Jim). You can get away with providing very little input if you maintain eye contact and nod your head every few seconds.