To do this effectively you should first put the keywords into a descriptive titles and subtitles, and then make use of the HTML H1, H2 and H3 tags.
Remember that the HTML H1 tags, defined by <H1></H1> will make the text within it a title
H2 tags, defined by <H2></H2> will make the text within it a sub-title.
H3 tags, defined by <H3></H3> will make the text within it a sub-sub-title.
With the arrival of HTML5 you can use these head tags more effectively. Prior to HTML5 content writer had to follow the order of the HTML head tags and so define a H1 tag, followed by H2 and H3 and so on.
With HTML5, you can restart the running order by grouping sections of text using the hgroup tag, defined as <hgroup></hgroup>
<h1>Topic Title 1 </h1>
<h2>Topic Sub-title 1</h2>
<h3>Topic Sub-Sub-title 1</h3>
<h1>Topic Title 2</h1>
<h2>Topic Sub-title 2 </h2>
<h3>Topic Sub-Sub-title 2</h3>
As shown above, each topic is enclosed in a set of <hgroup> tags. Each topic has its very own heading, sub heading and another sub heading. This illustrates how you to use the running order of H1 tags and so on within each <hgroup> and also continue the running order on the rest of the page.
To do this effectively you should place keywords 1 to 3 times at the beginning of your first paragraph and do the same in the last paragraph of you text.
You should also mention your main keywords through out the text.
One high recommended strategy is to write as if you were talking to someone such as a client or customer.
One way to do this is to write so that you are addressing the problem the customer has. For example, if your business is a plumber, your text should persuade the customer why the customer should choose your business and its services.
In addition to the above, you should also use variations of your keywords so as to maximize the traffic from the search engines for the keywords you have chosen.
Be warned! If the text you write reads with so many keywords words mentioned to often then will be seen as spam by the search engines. This will lead to the page and possibly the entire website being punished severely by Google and other search engines.