Answer:
Forget that you’re up there not to promote how wonderful you are, but to provide value to the audience.
Lose focus of what the audience needs from you. One way: Before you start talking, ask, “What do you hope to learn/achieve from this meeting?”
Fail to set objectives. Even if you don’t share them with participants, know what you want to achieve.
Proceed without a plan (also known as an agenda). Whatever you call it, it’s a map for how your session is going to go.
Wing it. Preparation is everything. Unless you’re an improv master, you have to figure out what you’re going to do, in what order and for how long. And almost everyone needs to practice.
Jump from point to point in a disorganized way. See #4 and #6.