Hi Charles,
Thanks for the clarification. What I'm going to give you here is a quick rundown, but I'll include some links at the end for further reading. I'll break this down into a numbered list for easier reading.
1. It's critical to understand that the most powerful element of your local search engine rankings is your website. This means that...
2. It needs to be well optimized in terms of traditional SEO factors and...
3. It needs to have strong local hooks in it. Your NAP (name, address, phone number) needs to be in all the right places (typically on your contact page and in your footer sitewide). Consider utilizing hCard or Schema to make your geographic signals as clear and strong as possible. Also...
4. The content on your website has got to be as good as you can make it. Go for thoroughness, depth, clarity and good local SEO on every page of the site. Look at what your competitors are doing and then do more.
5. Because the website has become such a key to rankings, everything you've ever learned about SEO and search engine rankings applies. So, this means the strength of your domain name, age of the site and such elements are likely factors as well as the whole linkbuilding aspect of SEO. It all counts.
6. Once you've got your site in shape (plus a plan for ongoing content development) you can look off the site for opportunities. These include the obvious, such as inclusion in Google Places and other local business indexes, and also the 'hidden', meaning citations. You mention in your post that you have tried a variety of things, but as you haven't mentioned citations, perhaps this is an area you've yet to explore. Citations are to Local SEO what links have always been to traditional SEO. Once upon a time, Google displayed some of a business' citations right on its Place Page, but they stopped doing that, making citation research more difficult for Local SEOs and business owners. This has led to the development of tools...
7. Right now, Whitespark's Citation Finder Tool is pretty much the standard in the Local SEO industry. There is a free version of the tool, but it's not very helpful. The paid version is great. Here is the link:
http://www.whitespark.ca/local-citation-finder/
8. And if you are are in the US or UK, don't miss Search Engine Land's post on the top 50 citation sources:
http://searchengineland.com/top-50-citation-sources-for-uk-us-local-businesses-104938
Essentially, you want to build as many citations as you can over time for your business.
9. Reviews are part of the scenario, too, but Google is still very unsophisticated in this area. Their ability to value quality vs. quantity has not been demonstrated. You do want to get as many reviews as you can...but there are just too many instances of businesses with, say, 20 reviews, outranking businesses with 100 of them to draw a truly clear picture of the correlation between reviews and rankings. They play a part, but they do not, in my opinion, compare in power to the website or the citations.
10. Returning back to point 6 and the obvious work...obvious though it may be, it's absolutely critical that you build a violation-free Google Place Page. If you don't read the guidelines, you are likely to make a mistake, because Google's rules are not intuitive. Here are the guidelines: http://support.google.com/places/bin/answer.py?hl=en&answer=107528
Hopefully, my answer will get you off to a good start. I highly investigate the following:
David Mihm's Local Search Ranking Factors:
http://www.davidmihm.com/local-search-ranking-factors.shtml
A recent webinar we had here:
http://www.seomoz.org/webinars/all-about-google-places
And become a regular reader of Mike Blumenthal's blog. Mike is widely considered to be North America's leading expert in Local:
blumenthals.com/blog
Cheers!
Miriam