You only have one chance to make a first impression. Therefore it is important to pay special attention to the beginning of your presentation. Make sure that the start is as best as it can get. Read more tips about the best start of a presentation in the book Public Speaking Excellence.
Besides the start also the end of a presentation is very memorable for your audience. This part leads to a peak in the attention and you should make good use of this. Therefore it is also important to pay special attention to the end of your presentation.
Specific tips about this you can also find the book Public Speaking Excellence.