Using SEO keywords is a great way to move up in the search engine results. If you use keywords properly you can get people to visit your site, but if you use them in an unethical way, you can get black-listed and taken off of search engine results.
Title
Make sure the title tag of the page has your keyword at least once. This is the first place that robots (spiders / crawlers) will look. It also helps the visitor know they are in the right section of your site.
Meta Tags
Use keywords in the meta tags. This includes the description meta tag along with the keyword meta tag. Stick to 150 characters in the meta tags. Google will not look at the keyword meta tag for keywords but most of the other search engines will.
Headings
Heading tags are very important for multiple things. They are needed for 508 compliant and of course to organize your page for your reader. When we talk about SEO, it’s another place to put a keyword. Use your keyword in your <h1> – <h6> tags.
Copy
When it comes to the actual copy of your page try and use your keyword throughout the page. But remember the important thing is to have good content that people want to read. The robots may index your site because of your keywords but people reading it will not stay if the copy is not good or doesn’t read well. The whole reason for having good SEO is to drive business, not just traffic to your site, and you can’t do that if visitors are bouncing off your site as soon as they arrive. Go back through after writing and reread what you wrote. If it feels like you are being redundant with the keywords, cut a few out.
Stemming
When creating keywords you can also do what’s called keyword stemming. Keyword stemming is using different variations of the word. An example would be “fish”, “fishing”, “fished”, and “fisher”. Search engines will pick up on the base of the word and using keyword stemming allows you to use the word more often and make it so the body is not so repetitive with the same keywords and adds a security blanket from being black-listed.
Images
Image tags are a good place to put keywords too. You need an alt tag if you’re doing 508 compliant so you might as well throw a keyword in there too. You can even use it in the title of the image.
File Naming
File names are another great way to use your keyword. Use no more than 50 characters for a file name. When naming your HTML files, using fewer characters makes it easier for the user to read and understand the path. Separate your keywords by dashes and do not use underscores or camel case. The search engines will read them as one word.
Conclusion
These are a few of the places that spiders and crawlers will look for information on your site. If you choose to only use one of these you will not get good results. It’s the combination of them that really affect the site and where it’s ranking.