1. Know your stuff
This is the number one hint I have to share. Sit down. Make a plan. Don't let anybody else do that for you. I prefer to do the slides myself as well. Practice often, practice hard. Your audience is taking the time to listen to you – so you should take the time to prepare.
2. Let the slides accompany your words
Don't read your presentation from the slides. I prefer to have as few words on my slides as possible. If you absolutely have to use text, make sure to use really huge fonts so the folks in the last row can still read your stuff. Rather use images to support your messages. Watch a couple of TED presentations for inspirations on how to create really great presentations.
3. If you do live coding, practice even harder
Beware of bad WIFI networks at the venue and have a plan B. If possible, prefer offline/local stuff. Prepare a finished version of your samples, so if anything goes wrong during the demo you don't have to start from scratch but can rather say "this is what it would have looked, I'll spare you the repetition".
4. Use Visual Studio's presenter mode
Install the Productivity Power Tools and hit Ctrl+Q. This will make sure to enlarge all fonts, again this is for our friends in the last row. While you're at tweaking Visual Studio, you can use Alt+Shift+Enter in any code window to get into full screen mode, using as much screen real estate as possible.
5. Sysinternals "ZoomIt" is a great tool for presentations
offering to zoom into certain areas of the screen and highlight stuff.
6. Engage with the audience
Use a presenter stick. This allows you to walk around the stage and get away from your computer during your presentation. You should of course stand up during your talk. If possible at all, remove anything that separates you from your audience. Don't hide behind a desk, be approachable. Accept questions during your talk and see if you can get into a communication with your audience. However, this needs some practice, as you need to be able to steer the communication if it gets too specific or moves too far away from your own track. Stay on course while looking left and right. If in doubt, collect questions and answer them at the end. Reserve time for such a Q&A block and have some optional content to fill the slot if there aren't enough questions.