Since I started making my presentations more beautiful, people have often asked me my secret. It’s not a secret, and it’s really quite simple to do.
First, realize that it’s not about you. It’s about your audience. Now, get and read a few good books on presentations. Your presentations, and your presentation skills, need to be good. You can’t just make things beautiful to compensate for badness in other areas. This is something I’m always working on.