As someone with one leg in the academic and the other in policy worlds, allow me to share with you common mistakes academics are vulnerable to commit when speaking to professional audiences. I wrote these down with the genuine belief that we need more trained and informed minds in the professional world, and hopefully help a new generation to ignore these, thus become better communicators and influence decision makers :
A) Stop complaining about time limits given to you at the start of your talk. Yes, we don't have a whole day for you to unload everything you know. In fact, if you cannot communicate clearly a topic in a focused fashion in 25 mins, then you might not be the expert on it. More irrelevant side points made gives impression that you don't actually know the core issue, or if you do, that it is burred under an avalanche.
B) Delete most power points, in fact, do not use them unless absolutely necessary. They always take longer than time given to you and distract your audience. You look amateurish as you keep skipping them, apologising and complaining about time given to you.
C) Think of your audience and what they need to know and what you are asked to provide, and not what you are interested in or happy to talk about. It is disrespectful to people who invited you, who won't invite you again.
D) Stop referring to your students in statements like "as I always say to my students". No one cares and that power and identity dynamic does not translate to professional world.
E) Mind the attitude. I know it might feel like you are gracing an audience, but till you win a Nobel... They are gracing you by sparing their precious time and inviting you. Your attitude sends a lot of undesired messages, and limits your future chances in those networks. Often, you might not realise that there are people in the audience with same academic qualifications as you, with more actual work experience on the issues you are speaking about and access to information you will never be able to read. A little humility won't hurt, but might be very useful.
F) Keep bios short and sweet, then on your CV you can make a giant roll of achievements (especially all those scholarships you got to pay your tuition fees ) and research interests, but in real life events, beyond a short paragraph it does not work.
G) Do realise, that in an academic setting asking interesting questions and problematising ideas are helpful exercises, whereas in professional settings they are not. Put forward your analysis, clear and tangible implications. It is not a postgraduate seminar, but a chance for you to help people who need to make actual decisions on issues with real life consequences.
I) Technical jargon within your discipline should be kept to bare necessity, and explained. Excessive use of words unique to your discipline and schools of thought you engage with do not work in professional settings and does not impress people.
J) You have a lot to give the world, often more than you realise. Half of your intellectual capital should be spent on knowledge, the other half on how that knowledge translates in addressing issues we face. The imbalance between the two is often visible to your audience.
K) Finally, this is a bit personal: fashion matters. When you are addressing a professional audience, you must dress accordingly. You might feel ideas matter more than how you present yourself, but surprisingly, even the postgraduate seminar fashion reflects particular social codes and dynamics. It is simply adapting to your audience, granted the aim is to influence them.