[meuk]

Make the objective of your talk clear. If you're giving an introduction to some technology, it is helpful to also point people to resources to learn more. If you need to explain or 'sell' your topic, do so, but don't overdo it. Also, be honest. Everyone appreciates enthusiasm, but it's better if you don't come across as a fanboy.

If you're having an interactive part, be aware that it is hard to estimate the time this part will take. If you have a hard deadline, be ready to skip some parts (this is a good idea in general as things may always

It's probably best if you are so familiar with the topic that you don't really need slides in the first place. On the other hand, take care to connect with your audience and take their background into consideration.