Put your content back on the new site, 301 any old domains you may have,

Build lots of high PR links.

Same problem with me last time, I make a 301 redirect for it. It take me 2 months before I gain back all my traffic... =.="

As you continue to build your site you will be removed from the sandbox. Its just basically googles filter for spam. So just keep building it.

Stop Paid Links
Just like a paid review, do this on other blogs that are dedicated to it. Even still intend to try this, use the process manually using the blogroll, do not use a script or plugin that easily detected by Google. I personally highly recommend creating a special website if you really want to make money online
Periodic updates.
Hiatus from the blog is okay, because there is no force, but do not be too long hiatus, will long rank position on the downside and the status can be changed to ex-blogger:-P
Avoid Duplicate Content.
If you’ve written an article on another blog, do not copy-paste the entire article. Use the Excerpt or the first paragraph of the article and then link to the source article.