This is number one on the list for a reason. It is very, very important to speak slowly and make pauses when needed.
Here's a good trick: have a bottle of water and take a sip from time to time. Five seconds of silence are useful to recover that lost minds that had been wandering for the last five minutes of your presentation. Silence gets audience back.
When I finally stopped acting like I had to race through my talk as fast as humanly possible, I finally started to calm down and actually focus on what I was talking about. The water trick is a good excuse for you to pause from time to time and take a break without it seeming awkward or forced.
Here's a good trick: have a bottle of water and take a sip from time to time. Five seconds of silence are useful to recover that lost minds that had been wandering for the last five minutes of your presentation. Silence gets audience back.