Barry Schwartz over at SERoundTable put together a solid Google Penalty “Check List” which I have added to:

- Fix trailing slash duplicate content issue through a 301 (this is due to a Google indexing bug)
- Fix ‘index.php’ duplicate content issue through a 301 (redirect this to the trailing slash: domain.com/index.php to domain.com/)
- Fix ‘www’ subdomain canonical duplicate content issue through a 301 (just doing regular canonical fix isn’t enough if you have subdomains)
- Remove all “dead” and irrelevant links
- Added a privacy policy
- Checked robots.txt -> verify nothing wrong
- Checked safebrowsing tool -> verify nothing wrong
- Checked meta tags -> verify nothing wrong (remove any unnecessary meta tags)
- Did you purchase or sell a SINGLE link?
- Build a couple of nice high-quality links through guest postings.
- Added new quality content
- Added noindex,follow on the individual tag-pages to prevent duplicate content
- Added the new canonical tag
- Removed interlinking
- Added valid and updated XML Sitemap

What if you do all the above, yet you still can’t rank? Consider the following:

- Your site might never have had a problem to begin with. It might have been one of those Google’s freak collateral damage issues that landed you in the soup.

- You correctly identified the issue, cleaned it up, filed a request, but you are in the “mandatory penalty period”, which you no idea how long it will last.

- You haven’t identified the problem or have partly addressed it and Google wants you to do more, a fact you are not aware of and are waiting endlessly for the penalty to end. The problem may or may not be stated as a warning in WMT.

- It might never have been a penalty by Google’s definition, but an algorithmic/filter tweak that has affected a select set of keywords pertaining to your domain. If the overall traffic hasn’t been affected drastically, perhaps a perceived penalty might belong to this category.

- Your site is affected (penalized or algorithmically tweaked), you undertake damage control efforts, file a request to Google citing what might have been the problem that you addressed, which might be a news to Google! So, they use the stick you gave to beat you.