I'm writing this as I'm working on a presentation for the TRB Applications Conference. I'm working on a presentation I can present, and my delusions of grandeur are such that I THINK I can present Open Source Tools to QC Transit Survey Data as well as Steve Jobs could present a new iPhone, but without the reality distortion field.
I've been to quite a few conferences of varying groups, and I would call these "semi-academic". Sometimes they are presenting research, but in many cases they are presenting an application of research. There's no selling, and the audience is generally captive.
1. The Presentation is to show your work and get attendees interested in reading your paper
In places where you aren't required to post a paper, do so anyway. Include the detail there. Don't include tables full of numbers in a presentation, highlight one or two important numbers (trends, alternative analyses, etc) and note conclusions. Include the big tables in the paper.
If you don't include a paper, upload a second presentation with more detail and/or use copious "slide notes". Seriously.
The last resort - go to WordPress.com or Blogger.com or something, build a blog, and post it there. Or hang it on your agency's website. Or something else along those lines.
2. Don't Include tables full of numbers
Even though I mention it above, it bears repeating. Normally, we can't read them in the audience. Focus on one number. For example, if you're showing that a mode choice model works better when using transfers as part of the transit utility, show us the log-likelihood or/and the correlation coefficient for ONLY the best case without transfers and the best case with transfers. Keep it simple. If I want the standard error of individual values, I'll look for them, and if I ask at the end of the presentation, direct me to the paper.
3. Just because you can read it on screen while authoring a presentation does not mean that your audience can read it on the projector
24 point font is a minimum. Yes, I know PowerPoint's list box goes down to 8. That does not mean you should ever go down there. Some people have sight problems, and those problems can be exacerbated by trying to see around peoples' heads.
A second part of this has to do with being able to read the slides while you're presentting. Just because you can read your slides on your 19"+ monitors at the office when you're 18" away does NOT mean that you'll e able to read them on a laptop with a 14" or 15" screen (or 17" widescreen, which is about as small due to the scaling) from a few feet away.
4. Use pictures and talk about them
If your presentation has no pictures, you're doing it wrong. If you want your concept/idea/solution/innovation/etc (pick one), throw in a few pictures that illustrate a point (or something like that). For example, in a presentation I'm working on now, I have a workplace location that is noted by Dilbert's office building and him waving. I think it gets the idea of "workplace" across to people, and most people know Dilbert.
More importantly, half my presentation is maps that I will talk about. No text. I have 7 slides with bullets, 2 or 3 with numbered lists, and that's out of 30. That's about right.
5. Reduce, but do not remove bullets
There is a big push in many circles to remove bullets from presentations. In an academic presentation, that's damn near impossible. Don't give in to the hate, but try to reduce bullets as much as practical.
6. Expect there to be dissenting opinions
I've seen a fair number of people get "blasted" by industry professionals. Don't get mad about it. They are normally not there to make you feel bad, and don't feel bad about it. A session moderator can recognize when someone is asking a real question as opposed to someone that has an ax to grind, and a moderator WILL step in if someone asking questions is out of line.
7. Do not use the Microsoft PowerPoint (etc.) templates
Rare is it that a Built-in Template works for a presentation. Normally an agency or company has some nicer and more appropriate templates to use. Use them.
This guideline does not apply if your presentation is short (e.g. 5 minutes) or it is a presentation in a non-professional setting (e.g. a hobby).
8. Do not read your slides
I can read quite well and so can the rest of the audience. If you're just going to read the slides, hand out your presentation (as good 'ol tree-killin' paper) and sit back down. Don't load your presentation on the laptop, don't talk, and tell the session moderator to just skip you.
This is probably the biggest reason many people want to remove bullets. No bullets means that you might have to (gasp!) TALK ABOUT your content!
9. Use Animations Sparingly
Do NOT use animations to simply put bullets on the screen. However, there are times when animations are important for the point of illustrating an idea, showing a process, or just pure entertainment.
10. Do NOT use numbers for alternatives
I will forget about the numbers as soon as you change slides. Give them names. And for those that have used "Alternative 1" and "Alternative 1A", there is a special place in Hell for you.
11. Have the similar delusions of grandeur to what I have
Find a person you think is a damn good presenter. Learn from them. Try to present as effectively as they do.
While I can't say that following these tips will make you the next great presenter, I CAN say that following these tips will help you NOT be part of the conversation that includes "THAT presentations was ATROCIOUS" and hopefully get you more towards "THAT presentation was AWESOME!"