Write a descriptive meta description (MEDIUM PRIORITY)
Search engines use the description meta tag as the description in their index. So it's important to describe your pages accurately. This helps customers find your pages, and search engines to index them.
Link to your page from within your site (MEDIUM PRIORITY)
Links are important, and linking from one page to another on your own site is a very easy way to get links. They aren't as important in search engine ranking as links from external sites, but they do help. If nothing else, they help the search engine spider find all the pages on your site.
Put up links that flow within the text (MEDIUM PRIORITY)
Links that make sense within the context of the document (whether from external or your own site) will rank higher than lists of links or other forms of artificial links. This is because search engines value content and links that make sense within the context of the content are more definitely related to that content than links that are inside lists.
Keep asking for inbound links (MEDIUM PRIORITY)
The older the links are the better. If you get 100 links added all at once, it appears to the search engines that you are buying link placement, and that can be construed as spamming.
Get linked in DMOZ and Yahoo! (MEDIUM PRIORITY)
Periodically check your outbound links for pagerank (MEDIUM PRIORITY)
Whenever you add an external link on your site, you run the risk that it changes from the site you linked to into a link farm or "bad neighborhood". By periodically checking the PageRank of the external sites you link to, you can remove links that have gotten bad. This will help you make sure that your page's credibility is not reduced by who you are linking to.
Link all major images (MEDIUM PRIORITY)
It's important to always link images because people click on images. And search engines value content that has been linked. The key is to always include alternative text, so that the search engine has text to rank. Any image that your customer can see on the page should be linked.
Keep your pages up-to-date (MEDIUM PRIORITY)
Pages that are regularly updated are given priority over pages that are older and ignored. But you should do more than simply fix typos or make small changes, regular, extensive updates are more effective than minor updates.
If you must use frames, always use the noframes tag (MEDIUM PRIORITY)
Frames and search engines don't mix well. But if you must use frames, then you should always include an extensive noframes version of your site. And by extensive, the best way to get your site indexed in search engines is to completely rewrite it in your noframes version.
If you must use Flash, always include alternative text (MEDIUM PRIORITY)
Flash and search engines don't mix well, but if you must use flash you should include alternate text that describes exactly what the Flash element includes. And if you use Flash for your entire site, you should always do an alternate version of the complete site in HTML so that search engines and non-Flash browsers can view it as well.