Best Seo Practices?

A lot of people look for technical tricks for SEO and ignore the big picture. You need both. Your SEO (and business) strategy is every bit as important as SEO tactics. There are more than 200 SEO factors that go into rankings, but here are a few of the more important SEO factors that I've experienced, both tactical and strategic:

• Have a website worth visiting. If your website isn't designed for users first, most of the time it won't do well in the search engines.
• Make your site crawlable. Don't rely on Flash or JavaScript navigation. If you need to use JavaScript, use it to enhance an existing (X)HTML menu, not create it. You won't even need a sitemap if your site is crawlable in the first place (but it doesn't hurt). RSS feeds also help you get crawled.
• Do your keyword research using Google's Keyword Tool. I guarantee that you're missing out on traffic opportunities if you don't do this (and most people don't). Take 5 minutes to make sure that your content is hitting the most popular search terms for its subject matter. It's worth it.
• Make a bigger website. Backlinks matter and internal links from your own pages count. The easiest, surest, and most efficient way to get backlinks is to increase the number of pages on your site. The bigger your search engine footprint, the more weight you have to throw around. This is one of the reasons blogs are recommended for SEO.
• Get your title right. You get 65 characters to create an on-topic incentive for the user to click on your search engine listing. Use the opportunity wisely. Your best keywords should be in the title. However, it's not just about using the right keywords; it's also about catching the user's attention while still signalling that your page is going to be relevant and helpful to them. Use Michael Masterson's Four U's Method: Be Unique. Be Useful. Be Urgent. Be Ultra-Specific. Stronger titles use more U's. Remember that your title is often used by social media sites to link to your page as well.
• Get your anchor text right. Use keywords that are also helpful to your users. Never use the infamous 'Click Here' or 'More...' text as a link.
• Get a handle on duplicate content. It's far too easy to create duplicate content. http://example.com, http://example.com/, http://www.example.com, and http://www.example.com/ are all considered different URLS. URL parameters also create duplicates: http://example.com?a=1&b=2 and http://example.com?b=2&a=1 are both different URLs. Use Apache or whatever server you're using to manage your redirect rules so this doesn't happen. This needs to be a consideration from the beginning and should be solved both programatically and with server redirects.
• Don't waste time asking for links. There is no bigger waste of time and money, IMO, than emailing other websites offering to do link exchanges. Think about the time spent searching for relevant websites, emailing, responding, and implementing a link exchange. What's your hourly wage? Now think about economies of scale and how many times you have to do that to make a discernible difference for every page of your website. There is no way that you can possibly come out on top. There are easier ways to get links.
• Make your site sharable. All those little social media widgets? They might be annoying, but when used properly, they make it easier for your users to share your content. The caveat here is proper context. Privacy policies, terms of use, registration, and other pages of that ilk are probably not good candidates for a widget.
• Viral content works. But you need to use it wisely. Not every announcement on your site is going to be or should be viral. It has to make sense and it needs to be well-thought-out. Ask yourself objectively, why would someone link to this? If you can't think of a good answer, you should go back to the drawing board. Again, the 4 U's help here.
• Incentivize linking. A great way to kickstart a viral campaign or even a more moderate but steadily growing external link profile. Think contests and giveaways, but also think StackOverflow's badge widgets.
• Build a community An audience of loyal readers will link to and share your content naturally. User-generated content increases your website's footprint and also incentivizes linking.
• Remember the big picture. Why are you doing SEO in the first place? What is the purpose of your website? It's easy to focus so much SEO that you lose sight of what you're trying to do. If you're trying to make money with your site, don't forget that you also need to focus on the usability, the design, the copy, the offer, the product, the checkout process, etc. SEO is only a small part of that.

If you're interested in more details, I wrote an article on my website about basic SEO tips which you can reference for more info.
Edit: Incidentally, one of the reasons StackOverflow does so well in the search engines is because it has an enormous community that continually produces keyword-laden pages. It gets a lot of the basic tactical SEO right too, but this is an excellent example of big-picture thinking that most people ignore. SEO is built into the design of the community as an extension of the way the community functions. That wasn't an accident.