Recently I have been attending a few professional conferences and giving talks in other countries. This is hard work, both for the presenter and audience. So here are some suggestions as to what is needed. Presenters need to invest the time and effort to make a presentation which can be easily understood by an audience with a diverse background and for whom English may not be their first language.
What to say
You need to introduce yourself, your organization and your topic. Tell the audience who your are and how you come to be involved in the topic of the talk. Tell them what it is you will talk about and how it will be useful to them. In may cases the audience can understand what they are being told, but not why they are being told it. Reassure the audience that details of the talk are available in their proceedings, on the web or from you later. This saves them worrying about taking detailed notes.
Have a clear outline of what you intend to talk about, show this to the audience and then stick to that. Have a clear start, middle and end to the talk. The audience will otherwise get lost as to where you are in the talk.
Stick to the topic and to your area of expertise. It is all too easy to stray from the topic and express your non-expert views on irrelevant topics, or worse show your ignorance of the areas of expertise of the other speakers and the audience.
Keep to time limits set for your presentation. Do not use up the question time with talking and do not run over time, even if the moderator seems to think it is okay. Part of being a professional is being disciplined and the credibility of a speaker on any topic can be destroyed by their being unable to stick to the time limits.
If invited by the moderator to introduce yourself, you should do so before saying anything else. Don't talk about the previous talk, about unrelated topics, or thank the organizer for inviting you, or talk about companies you are not associated with. The audience will be sitting there wondering "who is this person?", "what are they trying to tell us". At the end of the talk it is okay to extemporize, after the audience know who you are and by what authority you speak.
In introducing yourself, or preparing the introduction for the moderator to read out, do not be too boastful, bit also not too modest. Customize the introduction for the topic and audience. If you had a major role in developing something you will be discussing, then include that. You can't assume the audience will know you foundered a company or were involved in developing a standard.
You should not say something is "interesting", or "fraught" or use slang such as "a plug", or terms such as "dramas". If it wasn't interesting you would not be talking about it. If it is "fraught" you need to explain in detail in what way, and use different words the audience is likely to know.
Don't ask the audience about local conditions, as it suggests you have not bothered doing any research.
When use the full expanded title of something before using the acronym. This is both to show you know and for people who will have difficulty distinguishing between an acronym and an English word they do not know.
You need to explain the government, legislative or other context, for example do not just mention some law, without saying which level of government and which country it was from.
When referring to another person, use their full name and their affiliation. Don't assume the audience will know who "Tom" is for example, even if they have seen them in a previous talk.
Do not insult or attack the conference organizers or the sponsors. If you have differences with those behind the conference, then you should not be speaking at it. Similarly do not blatantly plug the conference or sponsors: the audience did not come to hear sales pitch.
Tell some person anecdotes to illustrate the points, but do not attempt to tell a joke unless you are very sure it will not be offensive to the audience or just not funny.
Slides should contain a small amount of very large legible text, illustrated with graphics and photos. You should include web or contact details on the last slide so people can find out more. Include references to source materials on the slides or in supplementary notes. Do not assume the audience will have the supplementary notes, as in many cases they will just have a copy of the slides.
The W3C has guidelines for accessible web design, intended for people with a disability, but these can also be used to make clearer materials for international audience.
Technology to help?
Conference organizers can help with presentations via better technology. Where there are several people on stage, it helps to have a screen at the foot of the stage facing the speakers which duplicates whatever is on the main display. This way the other participants do not need to crane their necks around and put their backs to the audience (which is impolite) to see what the presenter is showing.
Also a very large countdown clock showing how many minutes the speaker has left is useful. Some KL pedestrian crossings have countdown clocks and this could be emulated with a computer application. It could have the display change from green to amber when time was almost up and then change to red for the last few minutes. This would be a polite way to remind the speaker to keep to time, as it is difficult to politely remind them.
Perhaps with some commercial presentations, where time is money, a more extreme intervention is needed. The speaker could be asked to nominate their summary and conclusion slides. The automated system would flip to the summary slide automatically when time was almost up and to the conclusion slide when time was up, taking control away from the presenter. That may sound Draconian, but where a presenter takes twice their allotted time, either due to poor presentation skills or in a misguided attempt to get more than their fair share, this can ruin an event.
You might consider going further and asking the speaker which was their summary slide and which was their conclusion slide, then have the system automatically override their presentation and flip to these slides. Moderators without these tools will just have to do their best to be firm with presenters, so as not to inconvenience the later speakers and the audience.