1. Having more slides in your slide-deck than you actually speak to.
2. Having more text written on your slides than you actually say.
5. Failure to visualise your work.
6. Failure to demonstrate relevance.
7. Using note-taking lingo as an abbr. strategy.
8. Bad design
I get really excited when a presentation’s about to start and the cover slide looks fab — but most of the time it’s a false start and when the presentation gets underway the content slides are cluttered and ugly.
I know you’re not a graphic designer. But slides like this are so busy I don’t know where to focus. And its just not nice to look at.
I’m not a graphic designer either, but here are some basic tricks to make your slides passably attractive:
a. Standardise everything as far as humanly possible, e.g.: make sure headings appear in exactly the same position from slide to slide; make sure your font size is the same on every slide; and make sure text boxes and images appear in similar locations. The standard slide layouts built into Keynote or Powerpoint are designed to help you do this. It’s for good reason. But you’ll want to override them, so…
b. Get familiar with how to set the position of objects exactly so that you can align them perfectly to one another and from slide to slide. In Powerpoint you go into format autoshape/object –> position and size
c. Try and use a maximum of two fonts — not to mix and match, but to distinguish between headings and body text.
d. Negative space (blank space) is your friend. Put less stuff on your slides. Aim for one message — one step in the story — per slide. Which leads on to…
e. Don’t get sucked in to thinking that there’s a magic number of slides you should use. It’s OK to have more slides than your colleagues if your slides are simple, uncluttered and you will move through them quickly while their slides are packed full of stuff and they’ll spend 5 mins talking through each slide. In fact the audience will find yours easier to digest.
f. Find some sites that produce stuff you like to look at (e.g something like StockLayouts). Use this as inspiration for things like ‘fashionable’ colour combinations and design ideas
g. Don’t be ashamed to utilise free templates available on line.
h. Read stuff by people who know what they’re doing like this or this.
i. Watch good presentations and get inspired. I get chills watching things from TED.
standing and waiting 
I give up, I really do. Whenever I use powerpoint, it seems to go WRONG, no matter how prepared I am in advance, and I get more stressed fiddling about with the jolly machine than giving a calm and engaging presentation. And fer what?
I feel your pain, Michael. I gave some lectures at UNSW a couple weeks ago, and I was so nervous I turned up three hours early so I could load my presentation and check that all the links worked while the room was empty. But it’s not often you’ve got that luxury…
None of the offences I’ve listed so far have to do with technical hitches, though. I’m happy to allow people the need for tech support (which is usually available in the context of an academic conference) — but I find it much harder to forgive bad content!