I’ve compiled a list of search engine optimization strategies that every web designer and website owner should keep in mind.

1. Update the site daily, in other words, add new material daily.
2. Use your keywords and description tags – one or two lines of text.
3. Other sites and pages should link to your site, bringing higher traffic.
4. Have original, quality content that will attract visitors and builds your brand.
5. Use video marketing.
6. Use social media.
7. Blog.
8. Work to increase your conversion rates.
9. Get your business on Google maps
10. Use mobile marketing.  Any website can be easily converted for mobile access.
11. Use tools such as Google Analytics to see which keyphrases result in the most goal conversions.
12. Try to stay away from 1-word (or possibly even 2-word) keyphrases that havethousands of competitive sites in the search results.
13. Use tools such as Wordtracker and the AdWords Keyword Suggestion tool to find relevant niche keyphrases with high search volume and low competition.
14. Allow your keywords to appear often, but not too often.
15. Use a sitemap.
16. Use the title tag.
17. Use the h1 and h2 headings in the page.
18. Link text (in links within the page, and in links from other pages).
19. Use readable page URLs.
20. Use the image alt text.
21. Use bold and italicized text.
22. Make use of the many free analysis tools out there, including: Yahoo! Site Explorer — Which lets you find out detailed search-engine-related info on each page of your site, including the most popular pages and the inbound links to each page.
Google Webmaster Tools — This gives you all sorts of details about how Google sees your site, such as problems crawling your pages and suggestions for how to improve your HTML.
23. Let Google, Bing, and Yahoo know about your site.
24. Make site accessible to screen readers.
25. Google Analytics — Reports on vital traffic data such as visitors, pageviews, traffic sources, keywords, and lots more. Also lets you set up goals so you can see how well your SEO campaigns are performing.
26. SEO Book and SEO Chat — these 2 sites offer a large range of free, Web-based SEO tools, many of which give you useful information about how your site is faring in the search results.
27. Do not duplicate content on multiple pages-lowers ranking.
28. Displaying your site at multiple domains — for example, www.example.com and example.com.  Choose one domain or the other, then use 301 redirects to ensure that everyone (including search engines) is looking at just the one domain.
29. Use plurals of keywords in meta tags.
30. Use misspells of keywords in meta tags (i.e. knifes).

I hope this list is useful to you.  I’m sure as time goes by, more SEO strategies will be in effect, so keep yourself updated!