My experience in giving talks? I've been presenting on the job since 1999. I've been presenting at conferences since autumn of 2008. This past year (2011) I gave a lot of talks, helped others with their talks, and did a number of cooperative talks where I shared the stage with another person. I've learned a lot, from my own mistakes and those of others. Since I like to share, here we go.
You aren't Steve Jobs
In terms of presenting, Steve Jobs was no mere mortal. He got away with wearing black in front of a black background. His slides were frequently dark. And he held up tiny objects in front of literally billions of people. He did all of this and got away with it.
Steve Jobs was billionaire leading a multi-billion dollar company. His presentations were highly choreographed affairs where every detail from lighting to audio to who got to attend was tightly controlled.
For example, Steve could wear black because of amazingly proficient stage lighting techniques. Carefully watch a high definition video of him showing off the latest product while in a black sweater and you'll see that he's literally standing in a column of light. Odds are most conferences don't have spotlights or fancy lighting, and even if they do - the stage crew are not being promised a bonus for doing it right and financial ruin if they fail.
What this means is be very, very careful about using the attributes of Steve's talks for inspiration or arguments on how you are going to do a talk.
What to wear
Bring several presentation shirts to the conference so you can be sure that what you are wearing shows up in front of the background. Be a little classy and wear a polo shirt instead of that t-shirt. If the background is the same as your shirt, go and change. If you don't have a shirt that works, go buy one or wear your jacket.
The reason being is the same as why Newscasters don't wear some colors on video. They don't want to look like floating heads and hands. It happens to them, it happens at technical conferences, and it will happen to you.
Black text on white background
I said it last year and I'll say it again: High contrast slides please. If a designer, manager, friend, or spouse tries to stick colored backgrounds or text into your slides, politely remind them that what shows up nicely on the monitor or laptop will absolutely fail to be appreciated by the attendees of the talk. Social media and IRC will be filled with comments about the unreadable colors of your slides.
Remember, unlike Steve Jobs, you have no control over the AV team or whatever the conference venue provides when it comes to projectors and screens. So play it as safe as possible.
I really prefer the black text on white background. The people in the vision community (arts, theatre, animantion, and eye doctors) all agree with me.
This past year I've had technical people (all with jobs outside the vision community) quote some interesting material about the validity of white text on black background, but I personally find it hard to read those slides if I'm in the back. Also, if the room is brightly lit, the letters are barely visible.
The happiest alternative I've seen was at a Mongo event, and was a certain shade of dark blue with bright yellow letters. However, I think like the black background, it would be suspect in the wrong light.
One last note: Don't use color gradients in your slides. Please.
Cheat at the command line!
I'm giving a talk today at Southern California Linux Exposition 10x called Intro to Python. It's inspired by folks like Raymond Hettinger and David Beazley. And the big thing I'll be doing is avoiding the command-line like the plague.
This is because the command-line is treacherous in front of an audience. Conference networks are notoriously prone to going down at the wrong moment. Same goes for laptops, especially when connecting to projector hardware it's never touched before.
Also, you know what it is like typing with someone looking over your shoulder? Imagine that times hundreds, or thousands when your video is being uploaded so people around the world can view it.
So either use something like PLayer Piano to record a command-line session in a docstring, or do what I do and use slide transitions to mock typing.
Be rested, fed, and sober for your talk.
In 2011 I watched a guy fumble through a talk with beer in hand, a personal hero of mine blearily try to get through his talk after a late night of drinking, and a couple people try to present after all-nighters.
Respect your audience and take care of yourself before the talk. Get some sleep, eat well, and drink moderately. This will really help you get invited to more events.
Practice, practice, practice
In the past I've said I don't practice much. If at all. Ahem...
It has been pointed out to me that I practice. A lot. Maybe not in front of a mirror, but I'm constantly going through my slides and coming up with things to say. I'll go through all my slides one-by-one and mouth what I'll be saying, and work out the timing of things. Which means that while I haven't been projecting my voice, I have been practicing.
In 2011 I did the curious thing of actually trying to practice on a couple presentations. And I have to say that I've seen a huge amount of improvement. I certainly felt more confident and I feel like the talk goes better! For example, A talk I gave at PyCon AU 2011 that had some issues after a lot of practice went smashingly better at DjangoCon 2011.
Push questions and comments to the end
Your talk should have a flow, a pace as it were. And lots of interruptions will cause you to lose your chain of thought, or cause the audience to lose focus. If someone asks a question during your talk, ask them to wait until the end.
If they keep asking questions or giving comments, ask them nicely to talk to you after your presentation. People are decent and will respond nicely to your request.
Sign up for Pycon US!
Early bird registration closes on January 25th. Sign up for it beforehand and you'll have enough money for a really good dinner with drinks. What are you waiting for? Go do it!