Don't start ANY sentences with "Look..." It's condesending and irritates the crap out of many people, especially me.
Avoid crutch phrases like "my friends", "folks", "you people" and so on. If comedians start using them for sound clips it means you need to get a new speech writer.
Learn to pronounce words properly. Note that I didn't say "correctly". Properly implies respect for colloquial enunciation. Don't stand in the city of Virginia Beach and mention the neighboring city of Norfolk as "Nor-fork". It's dumb. No. It's stupid dumb.
Respect American general enunciations for words like "Nuclear". It's "Nu-clear". Come on. Say it with me: "New-Clear". It's not that hard. You can run for office, you can also pronounce thing properly.
Promote yourself - Do not Demote your opponent. If you mention your "opponent" more than twice in any event you are clearly saying to everyone: "I've run out of original ideas. I have nothing new to say. I have no real plan for what to do. I'm completely lost and stupid as hell ". We want to hear about YOUR plans and how YOU will fix things. Mud-slinging is for 3 year olds.
Promote the Positive. If your TV ads focus on what your opponent does wrong more often than stating what YOU plan to do, you're out of gas. We've already heard all the problems. Tell us how you're going to fix them.
Avoid saying things like "I'm going to..." and "I will..." unless you immediately follow each one of those with an explicit explanation of "How". Anything else is just lying and BS.
Avoid the Half-Truths. This is the Internet age. Anything that you claim as fact can be validated in minutes and either proven or disproven. Saying things which are twisted truths will only vilify yourself and lead to public embarrassment.
Now, all that said: Put up or shut up. Let's get the vote on.