The best place to begin when creating a keyword rich website is with existing copy. Why? Because the message is more important than the search engine ranking. You may disagree - after all, what's the use of having compelling copy if nobody reads it? This is a valid point, but I strongly believe that the opposite scenario is far, far worse: a highly visible site that is notoriously full of garbage.

This is particularly important for content-based sites that offer information as their primary benefit to readers. You can bait them by stuffing your copy full of irrelevant keywords (i.e. "Looking for debt consolidation facts for your debt consolidation problems? Many consumers seeking debt consolidation tips find the debt consolidation information from our stellar debt consolidation blog to be highly beneficial when tackling their debt consolidation problems...") but it won't take long for a reader to discover that you were just after their clicks. Next time your domain name shows up in a list of search results, they'll pass.

So, write your information first - especially if you are working within the confines of a word count limit. You'd be surprised how quickly you can hit 250 words by working in keywords but never really getting to the heart of the matter. Start without any keywords in mind - don't even do any keyword research yet. For now, these are your main concerns:

* Hooking your reader
* Defining the issue
* Providing a solution or insight into the matter
* Leading the way to the next action

I'll go into further detail on those particular items in later posts. But for now, let's assume that you've written a succinct, informative and entertaining piece. Now, let's keyword it.
Get Yourself some Keywords

The first step to beefing up the keyword content in your copy is building a keyword list. You may already have a few keywords in mind. I like to have one keyword per every 100 words of text, capping off around 5 to 7 keywords (though most web content won't get longer than 500 words). To come up with keywords, simply imagine that you are searching for the product or information discussed on your page. What kinds of search terms would you use? Which combinations of words? Next, plug them into Google's Keyword Tool in order to refine them. Go for some keywords of varying lengths - have a strong one or two word keyword and then supplement it with some longer tailed keywords as well.
Search and Swap

After you have a nice list of keywords, start reading through your text for "swappable" phrases. These will vary depending on your topic, but typically, they are non-descriptive terms - such as "product" or "service" or "item." Exchange generic words for keywords wherever possible, but of course, don't inundate the reader with repetitious language.

Next, try to work in your long tail keywords. This is easier than you think and can easily be accomplished by re-ordering longer sentences. The main perk of long tail keywords is that they often contain shorter keywords as well. For instance, take "Small businesses see a significant boost in return visitors after consulting with a professional web design firm" and make it into "Small business web design consultants can vastly increase the number of return visitors" and you have effectively worked in the long tail keyword "small business web design" without bogging down the sentence or drastically changing the meaning. As a plus, you've also mentioned another keyword: "web design consultants" in the very same sentence, re-using some of the very same words. It's kind of like hitting a multiplier square in Scrabble.
Headings

After you've doctored the content, it's time to focus on the headings and subheadings. If you don't have any headings, add them in now! Search engines and humans alike prefer text that is broken up occasionally, making it another double-whammy for SEO and reader-friendliness. Look for natural transitions between paragraphs where you can group your information under a title and heading. If there aren't logical breaks, then you may want to take this time to reorganize your information anyway.

Once you have your headings in place, try to work in some keywords. Don't go overboard - one keyword per heading is plenty. And don't repeat keywords between headings. Anything that is big and bold has plenty of emphasis already - repeating it will wear it out.
Finish it up

Run your page through a keyword density tool and make sure that you are hitting your target. If you are way over on one keyword, try swapping terms around to balance it out.

Next, read your copy out loud to make sure it flows. Let it rest for a couple of minutes, or even an entire day in the off chance you have the time, and read it again with fresh eyes. Better yet, let someone else read it. If they think it sounds stilted and arduous, go back to the drawing board. Remember: readability is king.