Recently, an in-depth session was held at SES San Francisco 2013 that delved into how webmasters could recover from Penguin, Panda and other penalties that Google may have imposed on your website. The session was targeted towards webmasters whose sites have suffered as a result of these updates and are unsure how to go about recovering their rankings.
Panda
The host kicked off the session by looking into the primary reason for websites being hit by Google's Panda algorithm. Essentially, if you have poor quality content on your site you're going to be affected. The exception to Panda rules is if you’re a big brand (such as Amazon) that has a very specific kind of site – they don’t necessarily need quality content in order to provide value.
Penguin
The host spoke about how Google's Penguin is actually an algorithmic detection, so it is unlikely that you will receive a message about the penalty in Webmaster Tools – your biggest clue will be a traffic drop. You will need to manually clean up the links on your website – determine whether they are good or bad and get rid of all the ones that are bad (you can try disavowing them).
Other Penalties
The host also looked into on-site manual penalty actions that can be taken against your website by Google. These can be applied to the site as a whole or just to a limited portion. More often than not, a penalty will arise out of cloaking or sneaky redirects (both of which are unethical SEO practices). Hidden content, keyword stuffing and thin content can also cause penalties.
If your website was affected by Google's Penguin or Panda updates or if it has received another sort of penalty from the search engine giant, we hope that the above information has provided you with a means of recovering. Don’t forget to submit a reconsideration request when you've cleaned up your site and make sure to document all the ways that you’ve tried to fix it up.