Speakers who handle question-and-answer sessions well have mastered the fine points too:
Give clear directions at the start of the question-and-answer session. Unless you have ground rules already laid, you can't resort to them without sounding like you are dodging questions.
Truly listen. Listening well is not a strong suit among many executives, but it's a crucial skill for an effective speaker.
Hear from everyone who has a question before returning to someone with a second question. If someone tries to monopolize, say you'll come back to that person after you've heard from other contributors, and make sure you've established this rule at the outset. You can hold off aggressive hand wavers by saying, "Will you hold it a moment, please? I believe this person on my far left is next."
Always recognize questions in order. When two or more people hold up their hands at the same time, recognize the first one you see, then mentally note the others and come back to them in order.
Don't develop any blind spots as you look for questions. Let your eyes roam over the entire room, including the head table or rostrum.
When you're asked a question, always repeat it before answering, because many people in the audience might not have heard it. I've been advising people to paraphrase the question. This assures you of a full understanding of the question. If necessary, ask for clarification. Repeating or restating the question is one way to clarify it: "As I understand it, you are asking..." Don't feel you have to repeat verbatim; you can always restate in a way that gives an impression you want to give. End by thanking the questioner.
Always look every questioner straight in the eye. Then answer the question briefly and accurately. Don't wander away from the point. Some questions may tempt you to make a speech in reply. Don't! You have already made your speech.
If you don't know the answer, don't bluff your way through it. Your listeners will have more respect for you if you're candid and say you don't know, but you can find out and get back to that person.
You may be able to score some important points by asking someone else in the audience to answer. For example, if you are asked a technical question and you know that Jack Jones in the back row is an expert, deflect the question to him: "That's a good question, but it is out of my range. Perhaps Jack can comment." You satisfy your questioner, and win the support of Jack Jones at the same time.
Save your second conclusion for the end of the question-and-answer session. Only end with someone else's question if it fully supports your position in a very memorable way. And even if that's the (rare) case, I still like to end the session myself. After all the time and effort you put into preparing your speech, why end on someone else's note?