As you prepare for your next class or presentation, imagine your audience asking the aforementioned question. If you can’t answer this, you are wasting your audience’s time (and they’ll be sure to remind you of that with their feedback).
Think carefully about how you can add value to your performance. If you are teaching a language, make sure that you are constantly providing phrases, expressions, and grammar that aren’t included in the lesson materials (provide content with full-sentence examples for extra utility). If you are giving a seminar or presentation, make your presentation interactive (if possible), so that the audience can experience what they are learning.
As an instructor, one way I measure my success in this regard is by glancing at my students’ notebooks. If, by the end of the class, their notebooks are filled with new information, I can prove that they have gained something from my presentation. For seminars, I make sure the audience has a chance to practice what they are learning so that when they return home, they can immediately apply the content with a sense of familiarity.
So, when you are preparing for your next presentation, make sure that your audience can noticeably get something out of it. This sounds like simple advice, but you would be surprised by how many presenters never consider it (otherwise, I wouldn’t be writing this). Instead of telling your audience how great your presentation is, let them experience it for themselves.