Next time you think that you have to give a presentation, think first about the object of the meeting. Don't fire up Powerpoint through some reflex action. I often use it to get thoughts in order without actually presenting the slides to anyone. I use a default template with 60pt headers and 36pt text which is a great enforcer of clarity of thought and economy in words. But that's maybe that's a sign that I need to organise myself somehow.
Feedback is good.