Designing websites for search engine optimization is certainly a must anymore. People search for any and everything and do so in not-so-easy-to-think-of ways either. For example, I remember being astonished when I first learned that people would actually type a websites entire URL into Google, instead of the actual URL bar! Here are some quick tips that I have found that work!

• URL structure - Search engines do indeed place weight on keywords that they can read within the URL itself. Anywhere within the URL is fair game here. The key is to make it readable. So, no more example.com/designingwebsiteforseo but rather example.com/designing-websites-for-seo. And yes, ideally "example" is a keyword as well.
• Sitemap - Google makes this very apparent that they want you to use these. There are several tools out there that can help you make one for free.
• Breadcrumbs - Breadcrumbs are a navagational item that help remind a visitor of where they are located within your site. As they dig deeper, they provide help for the visitor to know where they are, but they serve the dual purpose of each page then having keywords that the search engine can pick up. An example of this would be something like, "home > electronics > music > iPod".
• Title tags - I have found this very rewarding with search engines. First, do place your keywords in the title tags. But secondly, re-think the order of those keywords being listed. Those first three to five words really get favored by the search engines.
• Redirects - Mostly used when changing pages or launching a completely new site. The must here is to use 301 redirects. This is a permanent redirect and transfers the SEO value you had for the old legacy page onto the new one. Using a 302 redirect is a temporary one and most likely will result in losing that precious SEO value.
• Linking - This is a much bigger topic, but in quick summary here goes. Link out and make yourself good enough that people will link back to you. Be careful of who you link to, but do do it!  The important thing there is to stay within your "community." So, a healthcare site linking to a Parkinson's research site is great and within the community, but a healthcare site linking to a plumbers website is questionable.
• Images - Name and optimize them thinking strategically. Use the alt tags like you were taught and make them all relevant to your sites keyword strategy.
• Headings - H4-H1, these should be used repeatedly with your keywords contained in them throughout the site.