I think the greatest emphasis must be placed on a solid campaign work ethic by the candidate at any local level. If there are fewer than 15-20,000 voters, the candidate who wants to win cannot afford to not go door to door. If they do that, the cannot afford to not have a memorable handout (in my campaign, I gave out notepads door to door).
Furthermore, candidates who really want to have the edge also cannot forget to personalize the rest of their outreach. Phone efforts should be targeted and personal, and direct mail should also be targeted to whatever extent possible. Sometimes this means personalizing the direct mail in some way, but in larger campaigns that may not be feasible.
I honestly think the reason I won and the reason our folks can win going forward is if we put in more work than the other guy. A lot of candidates for local and even state legislative office simply assume that if they follow the formula, maybe get a good consultant, thats all they really need to do.
The best candidates devote the period of time preceding their primary/election to campaigning, and make as many personal connections with voters as possible.
A campaign message should be memorable by being succinct. Detail is for websites and Q&A sessions, not flyers, handouts, or even stump speeches. Voters will only remember one or two things about most candidates, if even that. If a voter can tell someone else on election day about a position you hold that they agree with, they will almost certainly vote for you, even if they would disagree with everything else if they knew all you stood for.
I know these are general points, I am typing on an iPad. But someone who wants to win any smaller office and is able to articulate themselves and their platform should be able to win a local office.
Dealing with bureaucrats and other elected officials is a much more difficult and frankly frustrating matter. That's for another discussion.