Create and submit an XML sitemap to enhance search engine site crawling in approved search engine formats and an HTML sitemap if required by the Web specification.
Make sure all the sites that should know about your pages are aware your site is online. If the project is a makeover use the link:colon tool to identify all incoming landing pages from back link sites and make sure that all landing pages [if obsolete] have their pages 301 redirected to new landing pages.
Make a site with a clear hierarchy and text links. Every page should be reachable from at least one static text link.
Make sure that your <title> elements and ALT attributes are descriptive and accurate.
Correct all broken links, crawl errors and other Google Webmaster suggestions have been corrected.
Keep the links on a given page to a reasonable number (fewer than 100).
Allow search bots to crawl your sites without session IDs or arguments that track their path through the site. These techniques are useful for tracking individual user behavior, but the access pattern of bots is entirely different. Using these techniques may result in incomplete indexing of your site, as bots may not be able to eliminate URLs that look different but actually point to the same page.
Make use of the robots.txt file on your web server. This file tells crawlers which directories can or cannot be crawled. Make sure it's current for your site so that you don't accidentally block the crawler.
Test your site to make sure that it appears correctly in different browsers.
Avoid hidden text or hidden links.
Don't use cloaking or sneaky redirects.
If the project is a Website makeover, use the site: Google search tool to check that all Web pages that are being taken down have been taken down.
Be sure to open a Google Webmaster account for the site or if one exists be sure to access the Webmaster home page. Once accessed make sure all Webmaster suggestions have been implemented.
Make sure you use only 301 redirects and not HTML redirects or other methods if the project is a makeover.