The goal of this article is to give you some concrete guidelines that you need to follow when you're optimizing your page. Some of the factors that I'll present have a greater impact on the search engines and others have quite a bit of controversy around them. I'll mention this supplementary information on each factor and I hope to make it clear to everybody.

Here are the factors :

1. The title tag

It is generally accepted that the title tag had, has and surely will have a great amount of importance in the eyes of a search engine. So be sure to make it descriptive for your site, unique for each of your page and also readable.

2. Keywords used in your document

Again, a factor with very little controversy around it and that is considered to have a big significance for your SEO. In short, if you want to rank well for a specific key word, you need to create good and quality contest related to that key word.

3. Internal linking structure

Be very careful on how you link to your internal pages. Choose descriptive anchor text and make sure every page is available within 3 clicks from your home page. Also, an internal page linked from your most important pages will probably rank pretty good, while a page buried deep inside your site will have a hard time getting crawled and indexed.

4. Unique content

Having content that has been copied from another older and more significant website will get you nowhere. You will get banned and it will probably take a long time until Google decides to take another go at your website.

5. Outgoing links

Choosing to link to the right websites may actually prove helpful. It is best to link to websites related to your content, but careful about overdoing it, or you might lose a considerable amount of visitors.

6. Website age

Your website age seems to play a smaller role in Yahoo and MSN algorithms, as new but content rich website seem to be able to rank well soon after they have been indexed. With Google, it's an entirely different story, as it seems to prefer older domains, even though their content is not as good as new websites.

7. The meta description tag

Alot less valued than in the past, because of the spamming it got, the description tag is still a tag to use because it has a bit of influence on the search engines, and even more, it may entice the people who search for your key words to click on your website.

8. Key words in your URL

Using your targeted keywords in your URL can tell the search engines that your website is more significant, and place it on a higher position. Use hyphens ( - ) to separate your keywords, or simply join them ( example : key1key2.com ). Don't use _ , because it is treated as a different keyword.

9. Alt and title tags

Using the alt and title tags for your images can also prove helpful, especially for images you can click on, as these tags will act just like the anchor text on a regular link.

10. H1, bold, italic and strong tags

Highly controversial, it seems that these tags still keep a little amount of importance, although alot less in the past, because they have been heavily spammed. Don't use them too much, or you might trigger a spam filter.

11. Page depth

In short, don't expect a webpage buried deep inside your site to rank well. Still, it isn't impossible it that page gets alot of inbound links or links from your most important internal pages.

12. Webpage language

Choosing the right website language can prove useful for regional searches, as your website may get a boost if the search is being made from a regional search engine ( example : google.jp ) or from an IP address in the same region.

13. Rate of content change

Some web pages rank well just by not changing for a long time, which shows they offer strong information, and others update their content very frequently and still manage to rank well. My advice is don't edit your pages just for the sake of fooling the search engines. If you do edit your pages, do it for your visitors.

14. Webpage size

Webpage size ( both in KB and in the number of words ) is not a very important factor, but you can notice that, for the highly competitive keywords, only websites with a considerable amount of content about that subject manage to rank well.

15. W3C validation

Although it is highly unlikely that a crawler checks if your website is W3C valid, validation is useful because you give the spider information about the char set you use, so it can interpret your page correctly. And, if it's a standard nowadays, why not go with it ?