It is worth cataloging the basic principles to be enforced to increase website traffic and search engine rankings.

Create a site with valuable content, products or services.
Place primary and secondary keywords within the first 25 words in your page content and spread them evenly throughout the document.

Research and use the right keywords/phrases to attract your target customers.
Use your keywords in the right fields and references within your web page. Like Title, META tags, Headers, etc.

Keep your site design simple so that your customers can navigate easily between web pages, find what they want and buy products and services.

Submit your web pages i.e. every web page and not just the home page, to the most popular search engines and directory services. Hire someone to do so, if required. Be sure this is a manual submission.
Do not engage an automated submission service.

Keep track of changes in search engine algorithms and processes and accordingly modify your web pages so your search engine ranking remains high. Use online tools and utilities to keep track of how your website is doing.

Monitor your competitors and the top ranked websites to see what they are doing right in the way of design, navigation, content, keywords, etc.

Use reports and logs from your web hosting company to see where your traffic is coming from. Analyze your visitor location and their incoming sources whether search engines or links from other sites and the keywords they used to find you.

Make your customer visit easy and give them plenty of ways to remember you in the form of newsletters, free reports, reduction coupons etc.

Demonstrate your industry and product or service expertise by writing and submitting articles for your website or for article banks so you are perceived as an expert in your field.
When selling products online, use simple payment and shipment methods to make your customer’s experience fast and easy.

When not sure, hire professionals. Though it may seem costly, but it is a lot less expensive than spending your money on a website which no one visits.

Don’t look at your website as a static brochure. Treat it as a dynamic, ever-changing sales tool and location, just like your real store to which your customers with the same seriousness.