A very nice piece; here are some pointers towards the end of the piece listing a mistake that I myself had committed and another that I had seen others commit:
Fortunately, most people asking questions at your presentation are simply seeking information or elaboration, so it’s best to approach the Q&A as an honest effort at intellectual exchange. By approaching sessions in this spirit, you are less likely to get defensive or hostile, and more likely to gain some helpful insight on how your research has been received, interpreted, and digested by your peers.
A few more words to the wise: You might be tempted to be more dismissive of a young-looking audience member who asks a long-winded question (perhaps assuming him to be a graduate student) than a full professor who is well known in your field.
Resist the temptation.
If you are curious, I committed the first mistake (during the early years of my research career, because, till then, it was always the teacher who asked the question, and being the teacher, he knew the answer and was trying to test me; so, I extrapolated the same to technical presentations too creating lots of unwanted unpleasantness all over. It was my sensible labmates and advisor who, slowly, but surely, lead me out of this hole of my own creation).
Hat tip: fabiorojas