1. Don't overthink keyword concentrations - To attract the attention of the big search engines you will probably set up landing pages that focus on local keywords or if your company is a local business, making sure your home page text has targeted keywords that links to pages within your website.  For example, if you sell tires near Louisville, you might combine some product-specific keywords with different neighborhoods and towns around the city.  Your SEO keyprhases might include "Goodyear Tires St. Matthews" or "Firestone Tires Jeffersontown".   Ideally your website content will have a 1-3 percent keyword density for each of these terms.  On the other hand, don't keyword stuff which means putting a ton of keywords on a page that really doesn't make sense just to get ranking.  The search engines watch for this.  To be safe, start with a few keywords in mind and write naturally.  You will get much more reliable results, especially in the long term.  If you have great content you don't have to worry about the search engine algorithm changes as you will be good to go.
  2. Putting local specific terms where they don't belong - Google's latest updates were focused on locale-specific information.  The search engine can tell the difference between well written content and content written just for SEO.  Your website pages should include some information on local areas.  They should not have paragraphs that resemble Wikipedia entries.  As an example, you might connect with target readers with a sentence that reads "Our tires will keep you safe while you roll across Shelbyville Road".   You will not get the same response and the search engines will punish you for using a sentence like "Louisville has a metropolitan population of 1.2 million.  Buy our tires."  Make sure local specific content makes sense on your site.
  3. Not monitoring statistics - Never assume that web users always use the same keywords or phrases when searching for a product or service.  You might need to target different keywords for different geographic areas. Your website analytics/statistics will show you that. Also look to see how long users are spending on each website or landing page.  Relevancy is important and well designed local SEO campaigns require constant quality checks.  Monitoring analytics and keyword use will help you keep your content fresh and valid.