1) During your run-throughs, notice words you might overuse to segue to the next idea, the word "so" is one of the most often abused. Reduce the number of times you use it or it'll start sounding like fingernails on a chalkboard.

2) In the spoken portion of your slide presentation, introduce each slide and make a summary statement at the end of each. These do not have to be on the slides themselves, but it will help the audience remember what you are presenting and prepare them for the next slide.

3) Know your material(concepts and ideas) backwards and forwards so you can avoid overpracticing. Once you've said the same thing enough times, it's hard not to lose that zest in your presentation and bore the audience to death. There should be enough information on the slides to cue your presentation so that you won't need notes.

4) Pause 1 second at the beginning of each slide to allow the audience to see what's on it before you start speaking.

5) I've found that the best way to practice and polish your presentation is to do it on a chalkboard or presentation pad, writing out the important statements and confusing words, draw the diagram in the way that will emphasize what you want to get across. It helps immensely with pacing and emphasis of all the right parts.