Positive ON-Page SEO Factors

Keyword in URL:
First word is best, second is second best, etc.

Keyword in Domain name:
Same as in page-name-with-hyphens

Keyword in Title tag:
Keyword in Title tag - close to beginning.Title tag 10 - 60 characters, no special characters.

Keyword in Description meta tag:
Shows theme - less than 200 chars.Google no longer "relies" upon this tag, but will often use it.

Keyword in Keyword metatag:
Shows theme - less than 10 words.Every word in this tag MUST appear somewhere in the body text. If not, it can be penalized for irrelevance.No single word should appear more than twice.If not, it may be considered spam. Google purportedly no longer uses this tag, but others do.

Keyword density in body text:
5 - 20% - (all keywords/ total words)Some report topic sensitivity - the keyword spamming hreshold % varies with the topic.

Individual keyword density:
1 - 6% - (each keyword/ total words)

Keyword in H1, H2 and H3:
Use Hx font style tags appropriately

Keyword font size:
"Strong is treated the same as bold, italic is treated the same as emphasis". Matt Cutts July 2006

Keyword proximity (for 2+ keywords):
Directly adjacent is best

Keyword phrase order:
Does word order in the page match word order in the query? Try to anticipate query, and match word order.

Keyword prominence (how early in page/tag):
Can be important at top of page, in bold, in large font

Keyword in alt text:
Should describe graphic - Do NOT fill with spam (Was part of Google Florida OOP - tripped a threshold - may still be in effect to some degree as a red flag, when summed with all other on-page optimization - total page optimization score - TPOS).

Keyword in links to site pages (anchor text):
Links out anchor text use keyword?

To internal pages- keywords? :
Link should contain keywords. The filename "linked to" should contain the keywords.Use hyphenated filenames, but not long ones - two or three hyphens only.

All Internal links valid?:
Validate all links to all pages on site. Use a free link checker. I like this one.

Efficient - tree-like structure:
TRY FOR two clicks to any page - no page deeper than 4 clicks

Intra-site linking:
Appropriate links between lower-level pages

To external pages- keywords?:
Google patent - Link only to good sites. Do not link to link farms. CAREFUL - Links can and do go bad, resulting in site demotion. Unfortunately, you must devote the time necessary to police your outgoing links - they are your responsibility.

Outgoing link Anchor Text:
Google patent - Should be on topic, descriptive Link stability over time Google patent - Avoid "Link Churn"

All External links valid?:
Validate all links periodically.

Less than 100 links out total:
Google says limit to 100, but readily accepts 2-3 times that number. ref 2k