I agree with what Howard mentioned, all great points.
I would like to add one more point to make a speech opening appealing:
Once you are standing on the stage in front of your audiences, make a pause, look around your audiences, not just a quick glance from left to right or vice versa, but make sure to make a few eye contacts to let your audiences feel that you are connecting with them. Then start with the speech.
I call this "a powerful silence" to start a speech.