Keywords are the key, pun intended, to search engine optimization. You must develop an understanding of what your prospects are looking for in your area of business. Keyword research is the method for doing this and a step that should be undertaken with great precision and effort.
Assuming you have nailed down your keywords, the question arises as to how to use them on the pages of your site. There are a lot of strategies that work and everyone swears by the one they use. That being said, making sure the primary keyword is emphasized on the page is one strategy that I certainly use frequently.
In my opinion, every page on your site should focus on one keyword phrase. Others prefer to go with a variety of keywords totaling no more than 13 to 15 total words. Each approach works, but you still have to determine the particular phrase you wish to emphasize. Once you have selected the phrase, it helps to draw the attention of the search engine to it by emphasizing it in some way. To do this, most people immediately think of enclosing it in bold html commands. This will work, but there is a better way.
Using heading commands such as H1, H2, H3 and so on are the best way to emphasize a keyword phrase. The commands tell the search engine robots that the enclosed text is the focus of the page. This can only help, but you have to be careful how to use them. Personally, I stick to using them for the title of the page, which corresponds to the keyword phrase I wish to focus on. Trying to use them in the middle of a paragraph of text is not advised as it looks horrific due.
One potential issue with these commands is there size. If you select a default H1, your text is going to be huge. You can counter this by redefining the size if you use cascading sheets. Regardless, make sure the primary keyword is emphasized on the page in one form or another.
