Designers - you must think about content
I know that when you’re designing a web site, you’re not thinking ANYTHING about content. But if your customer wants ‘design with SEO in mind’, you should consider the copy, even if you’re not writing it.
First off, you want to have your keywords (See previous post). That list will need to be handed over to the copy writer. The keywords need to broken down by page, which may be the job of the copy writer, or the designer, depending upon your experience with the market. At any rate, the copy should be written in such a way that it naturally uses the keywords chosen for each page. You don’t want to keyword STUFF, which tends to make the content seem extremely unnatural. Although the search engines aren’t thinking like humans (yet), they do have very sophisticated filters that will be able to tell stuffed content. Another thing to consider is your reader - sure you want to get traffic TO YOUR SITE, but if they flee immediately because the content is unreadable, what have you really achieved?
Susan Sparza from Bruce Clay, Inc. has an excellent breakdown of writing for SEO (first published in the SEO News). Read a copy of Writing for Search Engines here.