So your site has been de-listed from the search engines, your losing money, you don’t know why Google would do such a horrible thing to a great user focused website, and you’re going to submit a reconsideration. I will start by saying that most website owners 85-90% can figure out the issues if they think hard enough, or by doing a little research can find out what issues their website has.
1. Research, Research, Research
Google quality guidelines include violations such as cloaking, link schemes, using automated programs to check rankings, hidden links or text, keyword stuffing, creating multiple domains or subdomains with the same content, creating pages that contain programs with malicious behavior, doorway pages, duplicate content due to affiliate programs. 
Cloaking: One way to uncover this is to use a program like SEO Browser to make sure what your showing Google and what the user sees are the same.
Link Schemes: You can head to Yahoo and do a link: command to drudge through your links to find any that might have been placed by someone outside the organization with malicious intent, or someone inside the organization just trying to “help out”.
Hidden Text: This can also be uncovered by using SEO browser.
Duplicate Sites: Maybe someone outside the organization has copied your site or created many versions of it on multiple domains, or maybe an internal error caused duplicates to be made. Either way you should check to make sure there is only 1 primary website in the search results. One way to accomplish this is to do an intitle:”your title tag of your home page” command in google. Usually when there are internal duplicates or someone steals your website they use the identical or nearly identical title tag. You can also take a snippet of text 8-10 words long and put it in quotes and search for it in Google, this will uncover duplications with your content set and could lead you to finding the issue.
Analytics: I would dig into your analytics program to find what day and time the drop happened, you can also check your referring keywords to determine if someone has hacked your site and placed hidden text or links with malicious intent on your website (you will start to see off topic keywords in the referrals).
Now onto writing the reconsideration request
1. Give Google a comprehensive background of your website.
This overview should include what you do, who your owned by (if you’re a large site), what the purpose and overall mission of the website is, and the goal of the website for a user.
2. What happened
This is where you will need all the research you had done up front to explain in depth what happened and when it happened. You will need to go into depth here so I would suggest taking the time to do the above mentioned research so you can paint a good picture of downfall of your website.
3. Honesty is the best policy, Google has heard every excuse in the book.
Growing up we are taught that honesty is the best policy and that although it may hurt up front to tell the truth, in the long run it will all work out for the best. This holds true for writing your reconsideration request as well. I feel comfortable in saying that 85-90% of the time if you do your research, read over the webmaster quality guidelines, and think back to marketing programs you have done for the site over the last few months, you will be able to come up with a few things that might not have been pearly white. I would also say that you don’t need to get real granular with this to the point of writing a 2 page paper about every link or every change you made to the website. But I would recommend coming clean if you have taken part in any of the above mentioned that violate the quality guidelines.
Wrap it up
So you have said your peace, confessed to any wrong doings, fixed the issues that you found with your research, and now are ready to conclude this reconsideration request. If you are sure you have fixed everything I would say something like “We have gone over the Google webmaster guidelines and can not find any violations. If there is still something that we are not seeing please let us know (they probably won’t let you know so don’t be discouraged if they don’t).
Give it your John Handcock
Sign your name, title, and website at the bottom. Don’t sign some fake name at the bottom of the reconsideration request or be deceptive, reconsideration requests require complete honesty and transparency even if it’s difficult.
Time to make it official
Head over to the reconsideration request webpage  and send it to Google. Don’t expect to hear anything back from them besides a basic email saying:
“We’ve received a request from a site owner to reconsider how we index the following site: yoursite.com
We’ll review the site. If we find that it’s no longer in violation of our Webmaster Guidelines , we’ll reconsider our indexing of the site. Please allow several weeks for the reconsideration request. We do review all requests, but unfortunately we can’t reply individually to each request.”
You will probably also receive an email from them when they have reviewed your request usually saying:
We received a request from a site owner to reconsider how we index the following site: yoursite.com.
We’ve now reviewed your site. When we review a site, we check to see if it’s in violation of our Webmaster Guidelines. If we don’t find any problems, we’ll reconsider our indexing of your site. If your site still doesn’t appear in our search results, check our Help Center for steps you can take.
Waiting is the hardest part
I would not go through and make anymore changes to our website, if you would like to add more content that is fine, but avoid making structural or changes that would affect large portions of the site. I will say though if you uncover major issues that you did not see in your initial research that blatantly violate Google’s quality guidelines I would fix them, but remember you most likely only have 1 maybe 2 chances to get your website back in the index so the more you can uncover during the research phase and less you have to put in another request the better.
We have helped many website through this process so if you would like LinchpinSEO to review your reconsideration request and provide consulting though this difficult time, please let us know and we will be glad to help you out.