I think part of the issue with talking like we do in our living room, or with our friends, is that articles like this focus purely on the execution of the presentation, and not enough on prepping the content and setting up a theme. The basic purpose of a presentation is to convey something to an audience. How many of us actually sit and think about the audience, and why they need to give you a few minutes of their time, before churning out slides? I believe that many presentations fail at a fundamental level because the content and sequence of presentation is not thought out well enough.
I think back to all the terrible presentations I did when I was in college, or when I presented at several academics conferences. People typically jump in front of PowerPoint/Keynote when it comes time to preparing for the presentation. By now you are already doomed, because you have given absolutely no thought to a theme, a story or a takeaway. After you set up a sequence of slides that's likely to be incoherent on first try, techniques like stopping your 'Ums' or practicing in front of a mirror can only get you so far. These are minituae that may help make you a good speaker, but won't fix the underlying issue that you haven't given enough thought about the content, theme or storyline. You have barely given a thought to your audience and why they care about your talk.
I recently became a Product Manger at a startup (was a developer for 5 years prior to that). Presenting, communicating and convincing is a big part of my job now and I've been iterating every week on getting better. Here is my take and what I've found to work for me. There are two parts to this:
- Content, Theme or Story: Please don't go to slides or bullets when you start preparations. In fact, stay away from slides till you have completely visualized what an ideal version of your talk should sound like. In other words, if you were to explain your startup, a weekend project or a cooking recipe to a handful of people in your living room, how would you go about doing it? What sequence of explanation makes most sense? What do you want the audience to take away. Think about this hard. Replay it over and over in your head. Talk to your peers and A/B test it over lunch/coffee. You'll figure out the basic structure of the talk soon enough. Getting to a slide set becomes a piece of cake after this. And you'll notice that when you go up in front of people that slides truly end up becoming an auxiliary to your presentation, instead of the primary focus point. I've seen a major difference in the quality of my presentation purely by the amount of work I put in refining the theme of the presentation. It gives you focus on what to talk about, and gives clarity to your audience as they listen to you.
- Delivery: This can be solved and made better with practice. This could get involve figuring out a routine, stopping your 'Ums' or practicing 150 times in front of the mirror. I have a much better and effective solution that will get teach you how to control nervousness, stop your 'Ums', and just generally train you into being confident while going up on stage (wow that last sentence sounds like a scam :)). No seriously though, take an Improv Class. They typically cost $200 for 8 sessions and is no where as intimidating as it sounds (take this from someone who used to be a very shy person). I guarantee that a few improv sessions teach you the fundamentals of conveying a non realistic scene to your audience will blow 150 practice sessions in front of the mirror.