This is very important question, How to improve existing website for better search result? SEO expert can handle it, how? There are just two important factors, one is SEO expert should be aware of search engine algorithm and second one to be aware how online visitor uses search engine to get some relevant result from it. For better search result for your website, no one can guarantee set responsible reason for well tuned article but it has to match with many other parameters too upon search engine read, crawl, index and store. As said, tuning keywords in your article might help you move from 80th page to at 10th page result list in search mode or even closer.