Two things i find important with a speech

Short it down 

There's an unfortunate temptation in a short speech to try to cram everything you have to say into a short time. Instead of trying to make the time fit the speech, however, recognize that you have to make your remarks fit the time allotted. If you've got five minutes to talk, you shouldn't have more than three main points.

Speak up 

All of your preparation, cutting, organizing, and emotion goes for naught if people can't hear you. If you have good audio equipment, use it. If not, at least start out by asking whether people can hear your voice. One trick: Ask the audience to raise their hands if they can hear you well. If you see a patch of people somewhere without their hands up, you know there's an issue you need to address.