1. Identify your target audience.
Before you can determine which words you need to use, you have to identify your target audience - who are you trying to reach? To use terms that are not relevant to that target audience minimizes your effectiveness. Know your audience. Research the sites they frequent. Learn their language. Make a list of terms used on those websites that relate and are also relevant to your organization, information, services or products.

2. Use the tools that are available.
You can do your homework to find websites and develop a great list of keywords, but invaribly you will miss a word or phrase that is in use. For this reason, I would suggested that you avail yourself of the numerous keyword research tools. Most free tools are ok but relatively weak by comparison with the programs for purchase.  If you're planning to invest money and time into optimizing your website, my advice would be that you utilize a strong keyword research tool.  

3. Think specific.
Who wouldn't like to be at the top of all searches with a broad general term describing their services? For example, as a website company in Nashville, Tennessee, it would be awesome if every time someone typed website company into the search bar of http://www.google.com/ a link to our website would appear at the top of the index list. However, that is not a reality.  To make it one would take massive amounts of time and resources. There are only a handful of websites that will ever reach that position. Instead, we put our focus on nashville website company. That narrows down the list. We could narrow it even further by using nashville tn php website design. The more specific your terminology, the better chance of reaching your exact audience. Statistics also show that your site visitor is 4 times more likely to use your services if they type in 4 or more words in a search bar to find you. Be clever. Look for terms that may have slipped under the radar and are not being targeted as much. 

4. Think locally.
In narrowing down your target audience and specific keywords, think in terms of your local market. In our case, we use nashville website design. If we were wanting to expand outside the Nashville area, we might use middle tn website design or tn website design. Local market not only means location on the map - it can mean community. For example, if you are promoting karate pads to karate students rather than wholesalers, resalers or the general public, you might use the term student karate pads. You're more apt to get more attention from students looking for karate pads rather than just anyone - not to say you will not get traffic from the others.  But it will help drive your target audience to you. 

5. Keep it relevant.
Use words and phrases that directly relate to your website content. Just getting high ranking and heavy traffic does not constitute SEO success. If you make a habit of using off-topic terms, you will not only knock your branding off balance by driving traffic away from your site, but you run a high risk of getting caught by the search engine companies and get penalized for it.  

6. KISS.
You've heard that term - Keep It Simple Stupid. Although you want to be specific with your target audience and terminology, you also want to keep your wording simple. Don't use extra words like and, of, or the. They only muddy the water. Most search engines are designed to eliminate those terms in the search. Let's look again at the example of our company. We would never use the nashville website design company. That is too wordy - nashville website design company or nashville website company will do. 

7. Monitor your traffic.
You need to keep an eye on relevance and referrals. Are the words you're promoting getting attention? And if so, where is the majority of your traffic coming from? The best way to do this is by employing a web analytics keyword monitoring tool. Generally, as you follow the traffic on your site, you become enlightened and sometimes amazed at how people are finding you.  Analytic tools can even show you where you are getting traffic from misspelled terms or other abnormalites.  

8. Constantly reevaluate
Remember that the Internet changes like clothing trends. What is important and works today probably won't look the same tomorrow. Websites are constantly popping up and changing the face of the Internet. MySpace and YouTube are here today, but what will be at the top of everyone's important list tomorrow. The same holds true for the terms that are used to find you. Continually evaluate where you stand. Where your traffic is coming from? Are people still finding you the way they used to? Is there anything that has changed in your market that could affect your placement or relevancy to the market?  Keep it fresh!