Googling for "tips for presentations" will give you a lot of useful links. I want to capture here some basic tips, specifically for technical conferences. Not much about beautiful slides but about readable ones. As an audience, I find it unfair when a talk is really good but the slides are unreadable!
- Find out about the resolution supported by the projector at the conference venue. Set your machine's resolution to the same and check your presentation. At times you'll find your text word-wrapped in weird ways or your pictures going outside the screen boundary.
- Do not rely on wifi. Most conference venues arrange for wifi but they are almost always flaky. Avoid running your slides off prezi.com directly. Avoid embedding YouTube streaming videos. Avoid a demo that needs an Internet connection. Keep things local.
Text & Colours
- Do not use low contrast colours. Especially between the slide background and the text. Audiences at any distance, close or far, will have difficulty reading your slides if you choose an Emacs-style scheme. I typically prefer a simple white background and black text, with some red or blue thrown in for effect.
- Use less text. But large font size. Keeps the audience focused on you. But also makes your slide readable from a distance. Having no text is better than having unreadable text.
- Avoid complex diagrams. Have labels in a large font. The audience should be able to comprehend the diagram quickly and without hurting their eyes.
- Use safe colours for text and diagrams. Basically common primary colours that have a good chance of being projected correctly. Some colours on your monitor look very different on a projected screen. Subtle colour variations get lost when projected, so do not rely on those.
- Avoid placing text or images towards the bottom of the screen. Most conferences have multiple tracks. This translates to small rooms cramped with a lot of chairs. The bottom of the screen is hidden from those sitting even a few rows behind.
- Adjust your editor's look and feel before taking a screenshot of code snippets. Choose a white background with dark text, and make the font size large.
- Have the code snippets ready on your machine in case the screenshots do not appear clearly. During the presentation, you could switch to your editor to show the code. Keep the editor in an easy-to-view colour scheme with a large font.
- Annotate code snippets where applicable. Helps the audience follow the parts you want to talk about.
Final advice: do a trial run, ideally at the venue itself, and get feedback.