Have META tags refresh no less than 30 seconds
Having a META tag that auto refreshes can help boost rankings, but tags that refresh more often than 30 seconds will be considered spam by search engines.
Include a Sitemap
Sitemaps make it easier for visitors to navigate your site, and allows search engines to index all your pages. Make sure that all pages are linked to one another and a text description is included.
Keep keyword density in a 1-2% range
Or more simply, for every 100 words of text, the keyword should appear once, twice at the most.
Don't keyword stuff
Having a density of greater than 2%, or even worse, hiding keywords where they can't be seen by human eyes will back fire and result in lower rankings or even blacklisting.
Name graphic files after keywords
One place where you can get away with getting in an extra keyword or two without keyword stuffing is to name the graphic files after the keywords you're shooting for. Keep the words separate from each other using hyphens (ex: delaware-incorporation-company.jpg).
Word count; 300-750
A minimum of 300 to a maximum of 750 words for each page allows for the keyword to appear enough without getting too drawn out. Too many words and no matter how much it's broken up, you'll lose your visitor.
Use uncommon keywords or phrases
Uncommon words and phrases have less competition, and can get higher rankings by default.
Occasionally use a longer or plural version of a keyword
By mixing up the spelling or making a plural of certain keywords, you can get those hits from an organic search (ex: incorporate- incorporation- incorporated).
Don't use small font size
Keep the font size of all text a readable size. Small text, especially size 1 is typically assumed to be spam or fluff, and can get the site penalized.
Avoid link exchanges; may just be link farms
Avoid the temptation to work with link exchange programs to build link popularity. Most are just link farms that have no useful content other than to have lists of links. Search engines despise these sites, and will usually penalize linked site that appear on them. Make any link trade with individual sites via reciprocation and avoid this problem.