1. Get Reviews (from real customers)
Set a goal to get one review per day from your happy customers. You want to have WAY MORE reviews than your local competition (think 10: 1 ratio). If the other guy has 2, you should have 20! This will position you as the clear local leader in the minds of your potential customers.
2. Add Photos and Videos
Upload the maximum number of photos and YouTube videos, including your company logo. Use photos of your staff, your office / shop, and a couple of personal shots to give your profile a human touch. Videos can include a tour of your facility or simple tips that are generally helpful.
3. Incorporate Keywords in the Business Description and Business Name
When listing your company name and describing what your company offers, be sure to include popular keyword phrases used by your potential customers. Keyword popularity can be found at google.com/sktool . Do not change your business name, but do append some relevant keywords like this …
RIGHT: Javier's Mexican Restaurant
4. Add a Coupon
Google provides printable coupon functionality on your business profile. Provide a compelling offer valid only for a limited time. Remember, this "painfully deep discount" is just a one-time loss leader, designed to get new customers to sample your services.
5. Create Links Back to Your Local Profile
Create links to your Google Local profile page from your website, your YouTube page, your articles, your forum posts, your blogs, etc.
This same tips also apply to Yahoo Local and Bing Local, so you've got some work to do!