I would like to share with you on-page optimization tips which if you will follow you will never regret:
1. Title tag within the Head tag is used to define the title of a Web page. The content of the Title tag is displayed by browsers on the Title bar located at the top of the browser window. Search engines use the Title tag to provide a link to the site matching the user's query. The text in the Title tag is one of the most important factors influencing search engine ranking algorithms. By populating your most important keywords in the Title tag, you dramatically increase the search engine ranking of the page for those keywords.
Keep your title short, roughly 10 to 64 characters including spaces, and if that length is not enough, no longer than 70. Google totally ignores every character over 100.
Including irrelevant words (not found on the page) to your title will weaken the impact on your targeted keywords. Also can trigger some search engines spam filters. Place your most targeted keyword phrases at the beginning of the title.
2. Description Meta tag provides a brief description of a Web page. It is important the description clearly descibes the purpose of the page. The importance of the Description tag as an element of the ranking algorithm has decreased significantly over years, but there are still search engines that support this tag. They log descriptions of the indexed pages and often display them with the Title in their results.
The length of a displayed description varies per search engine. Therefore you should place the most important keywords at the beginning of the first sentence and this will guarantee that both searches and search engines will see the most important information about your that page. But only where possible.
Keep your description not shorter than 50 characters, and not longer than 149 characters including spaces (Google displays 154, but other SE less). And longer is fully worthless as most search engines do not consider this tag deeply, if not at all anyway. If you really think must be longer, it will be fine, if it is not longer than 200 characters including spaces.
Be aware that if you are adding there irrelevant words can trigger some search engines spam filters. Take care that the tag is relevant to the page theme. Avoid adding text not found in the visible text of the page.
To recap, description meta tags are not made for search engines. They are made for humans. So write a text that sales to convert, and achieve the best "Return On Your Search Engine Marketing Campaign Investment.
3. Keywords Meta tag lists the words or phrases about the contents of the Web page. This tag provides some additional text for crawler-based search engines. However because of frequent attempts to abuse their system, most search engines ignore this tag. Please note that none of the major crawler-based search engines except Inktomi provide support for the Keywords Meta tag.
Similar to the description tag, there is a limit in the number of captured characters in Keywords meta tag. Keep the tag to a minimum or 4 and maximum of 8 keywords or keyphrases and separated by comma (,).
Make sure that the keywords appear at least once in your content (body). If not, the keyword will be considered as irrelevant spam. Avoid repetitions as some search engines can penalize your rankings. Move the most important keywords to the beginning to increase their prominence for engines that still might take this tag into consideration.
Heading Tags (H1-H6)
A header tag is nothing else than a headline.
You should have a clearly defined <H1> header tag on each page saying to the reader, and to the search engines, "This is the primary subject of this page". Chose the primary search phrase of each page you are targeting.
It is important the keyword is present in the very first heading tag on the page regardless of its type. If the keyword is also used as a first word, you will raise its prominence.
There are standard rules for the structure of HTML pages. They are written in a document-like fashion. In a document, you start with the title, then a major heading that usually describes the main purpose of the section. Subheadings highlight the key points of each subsection. Many search engines rank the words found in headings higher than the words found in the text of the document. Some search engines incorporate keywords by looking at all the heading tags on a page.
Don't try to stuff to stuff your heading tag with many or irrelevant to the page content keywords.
Having multiple <h1> tags may now actually be subject to a penalty by the search engines, and is seen in the same light as "keyword stuffing".
You can certainly have multiple headlines appearing on a page, like <h2>,<h3>, e.t.c., for instance for sub-sections. But make sure that they are following a hierarchical order.
To be specific, the <h1> should be the first heading tag, followed by the <h2>, then the <h3>, and so on.
Many webmasters and inexperienced or unethical SEOs abuse the use of this attribute, trying to stuff it with keywords, hoping to achieve a certain keyword density, which is not as relevant for rankings now as it once was.
Read my tutorial for howto: Alt Attribute & Image Search Engine Optimization - SEO Workers
Use the semantical tags <strong> and <em> tags for targeted keywords within the visible content of your pages. But do not overdo it.
Those tags are alternatives to the <b> and <i> tags which you can use too, but I don't, since they are for visual presentation purposes only.
Pages Visible Content
Content is the food of search engines.
Try to have a minimum of 200 and no more than 700 words in the visible content area of your pages. Pages with too less content are generally treated as second hand pages, and they go into the unlabeled supplemental results, which cause a PageRank (not ranking) dilute. If you have pages longer than 700 words, it would be better to split into more pages.
Broken Links & Correct HTML
Check for broken links and correct HTML.
Sure not all errors are critical or can choke the spiders, but if you cannot make the difference, it is an issue to be taken into consideration.
Free tool to find broken links: Find broken links on your site with Xenu's Link Sleuth (TM)
Free tool to check your HTML: CSE HTML Validator Lite - FREE HTML Editor and Syntax Checker for Windows
Canonicalization is the process of picking the best url when there are different choices, and it usually refers to the homepage. For example, many people would consider these urls as same:
You can solve the problem with redirects. If you are hosting on Apache you can check here howto: .htaccess files - Ultimate .htaccess TutorialCode:example.com example.com/ example.com/index.htm example.com/index.htm example.com/index.asp example.com/index.php e.t.c
If not, here are some server side scripting solutions: Search Engine Friendly Permanent Redirects - SEO Workers
PageRank Sculpting (Siloin) & Robots.txt
If you did all above, before you start building links you can control the flow of PageRank to boost your most important pages and keep them out of the Supplemental Index. You must take care that the most important web pages like i.e the most lucrative products or services have not been been moved to Google’s supplemental index. Why?
The pages that show up first for any searches are the ones in the main index. The only time you will see pages from the supplemental index, is if there are not many, or any results for that term in the main index.
You can achieve that creating and upload a robots.txt file in your root /main) directory.
Here is an example a robots.txt I created recently for a customer: http://www.gameshop.gr/robots.txt
Please be careful and do not use that robots.txt for your site. It is just a sample. Every site needs a robots.txt tailored for its own needs.
Here is a basic robots.txt tutorial provided by Google: Creating a robots.txt file - Webmasters/Site owners Help
Prevent Search Engines Index your Secure Pages (https). If you are hosting on Apache you can check here howto: Preventing Search Engine Indexing of Secure Pages - SEO Workers
Checking the spelling of the text on your web site is very important; to ensure good content accessibility and readability for your readers, and better crawlability and indexing for search engines.
If you follow all the above tips, I hardly believe that you will need an SEO Expert or a so called Guru to do your on-page SEO work.
If I missed anything, please feel free and add it to this thread.
Thanks in advance for your contribution and good luck!