If you can stand another post with suggestions, here goes:
Do have some slides, but keep them to about one per 3-5 minutes of talking…so flesh them out accordingly.
Slides - less is more. Not in their number, but in what you cram into them. Each should have a larger font for a title, and then perhaps 3-6 somewhat cryptic points below it. Slides that look too busy are distracting and confusing.
Do talk to the slides. Just remember to look at your audience at least once each slide. (of course, I am being funny. You can use your slides as cues to where to go next as you stall or run out of interesting things/questions from the audience if you take them).
It is a good idea to do a full, real-time rehearsal, and do have a script. Not a word-for-word, but as stated previously, a well spaced, well written, and organized outline. In fact Power Point offers you that, complete with small inserts showing your slides.
However, the very best preparatory mechansim is actually knowing your subject. It is this single factor, more than any other, that allows you to speak extemporaneously (off the top of your head), that will convince the audience you are a winner and that they are likely to leave well informed. It is this capacity that will allow you to field questions and to do it with verve and with humour.
Avoid hubris. Focus, and respect your audience. If you allow yourself to get too cocky after you have warmed to the subject, you will say something that you will remember all of your life 'cuz it will be as embarrassing as aitch every time you recall it…about 30 times over your lifetime. It gets worse each time because you have more experience to judge just how awful an episode it really was. Do you wonder how I know this?
That’s about it. Knowledge, preparation, practice, and then a careful delivery. By the way, I just modeled one refinement for good spea