Hey, dear visitor, you’re probably wondering how to get more search engine traffic for your website. On site optimization is the thing that is really not as hard as getting more links etc, but it’s effectiveness is simply incredible.
Titles and Descriptions
Titles are vital. Make sure every page on yor site/blog has a relevant, keyword rich and unique title.
So if the page is about, say, Real estate in Arizona make sure that the title looks like "Real Estate in Arizona. Best offers on real estate", notice that the "real estate" keyword is duplicated in the title, this is a very nice technique to optimize your titles.
Make descriptions informative and attention catching, keywords don’t really matter here. Try to fit a short overview of the page’s content in the description.
Urls
If your url looks like "http://bestsiteintheworld/sdkakfsjfk213kfjaksjf" it won’t do you no good.
- Try to make urls human understandable and make them keyword rich.
- Also keep in mind that search engines ignore word like "to, from, and" etc in the links.
- Don’t make urls too long, Google hates it.
Cross Linking
Make sure that the pages of your site are cross linked in every way possible with good keyword link anchor text.
Make search engines bot live’s easier 
try to cross link your content so when the bot hits the frontpage - it indexes every page of the site. Say, you have a news site, just add 2 links to the bottom of every article: previous: Name of article and Next: Name of article. Breadcrumbs are a good thing to have too.
Avoid duplicate content
There’s a real nasty thing @ Google called "Supplemental index", where they put web pages that aren’t going to rank for anything important. I have unique content on my site, why would I worry about something like that, you might say. Wrong, there are convenient things for users such as tags, archives etc. which duplicate the content right at your site. Say, you have a "I am Awesome" article at your blog. You tag it with pure awesomeness tag, put it in 3 categories, and it goes to archives. Oh my, that’s hell lot of duplicates for Google’s bot. So it goes to the supplemental index and isn’t ranked the way you wanted it to.
Make sure you deny the search engine bots access to pages like these and you’ll do fine. It can be done either by adding the "nofollow" attribute to the link, or by denying these pages in the robots.txt file (this way is easier better).
Create a robots.txt file and put in the root folder of your site/blog. Read this robots.txt faq for more information how to disallow search engine bots from indexing content you don’t want it to index.
A neat checklist can be found at SeoMoz.
Know any other ways or special techniques of on site optimization? Comment.
Why? 
Happy blogging.
