CSS Tricks
The traditional ruler of the Website development and website coding, HTML received an add-on in form of CSS or Cascading Style Sheets. This is a new technique for website coding that enables alteration of visual presentation of web pages without actually using HTML. Add to it the advantage of JavaScript to in and Bingo! You get a perfect tool to play with the search engine crawlers and make them get you great search engine rankings. However, it may not be perfectly safe but still you can use them cautiously.

In the stone age of search engines (around 1998) a number of web promoters tricked the crawlers by adding hidden text to the web pages. This hidden text carried nothing but an incorrigible list of key words and phrases in varying combinations, repeated over an over again. Search engines soon started banning the web pages carrying such a dirty gimmick to get search engine ranking. However, CSS added a twist to this old tale. It enables you to add hidden text to the web page without getting you in the bad books of the crawlers. 

Another CSS trick is making links vanish. Link popularity is an important criterion in search engine ranking. A number of search engines consider the outbound links when they rank your page. However you may not want your customers to be redirected to the website of a potential competitor. CSS gives you the option of keeping these links hidden from the eyes of human visitors. It takes advantage of crawlers’ inability to see what comes up on screen. 

Search engines give additional weight age to the text that appears in bold and italics. Canceling the visual changes caused by the bold and italic tags is fairly uncomplicated. After these changes have been incorporated it is quite easy to fool the search engines into thinking that your keyword is bolded or in italics. H1 headings can also be made to imitate normal text.

Some of the search engines might consider the above-mentioned CSS tricks as Spam and may simply ban your sites from their listings. Though it is safer to use CSS for SEO tricks rather than using HTML still it is not completely safe either. Besides these tricks, CSS can be used to build your layout or to adjust the size of your headings and body text.