Note, that I do not propose the magic advices of how avoid AdSense possible ban. Because, there might be reasons beyond Webmaster control or related to the AdSense stuff mistake. However, it is possible to decrease danger of the ban, carefully following the AdSense Team recommendation and common sense.
Note, that getting Google to reconsider the cancellation note is next to impossible, if your site does not accumulate amount of traffic that might get Google sorry for losing you. So the easiest way to handle the situation is not to find yourself in it.
2. Do not make any changes in your AdWords code, other than playing with permitted color palettes modification.
3. Do not place AdSense code on Thank You pages, registration pages, or any other pages that do not contain real content.
4. Avoid insertion of AdSense code on your pages containing ads from Google’s competitors as, for example, Yahoo Publishers Network.
5. Do not use “hidden text” techniques on your pages, including tiny text fonts, or text with the same color as background.
6. Do not place your AdSense ads in the close proximity to Macromedia Flash games, pop-ups and download prompts, drop-downs and menu links, as it increases chances of the accidental clicks on the AdSense ads.
7. Avoid placement of too many links on your site. Having a link higher than 100 on a single page will classify you as a link farm.
8. Avoid using doorways - pages loaded with choice keyword ads redirecting visitors to another pages. While you can find many reasons of them being useful, AdSense will not share this point of view.
9. Stay away from running AdSense ads on pages, containing adult or mature images and videos, and racial intolerance and extreme violence exposing posts.
10. It is not recommended to place AdSense ads on pages, involved in unauthorized distribution of copyrighted materials.
11. Do not use the shared computer to log in your AdSense account, as your family members might accidentally spoil your situation.
12. Do not make any arrangements with other AdSense users on the clicks exchange. Any unusual traffic pattern is clearly visible the AdSense monitors through IP addresses used.
13. It is also not advised to be part of the traffic exchange networks or programs to boost your traffic, and especially AdSense exchange networks. While amount, involved in the cross-clicking will be higher than one-to-one, it is still will be a limited group of people, creating a statistically visible pattern, that might drew a close look from AdSense inspectors.
14. It is not recommended to utilize auto-surfing programs to boost traffic to your Web Site or Blog. Traffic generated from these programs is not considered as real for AdSense, and might be a reason for the ban.
15. Read all the Google AdSense policies, posted on the site to see whether your page might be somehow considered violating any policies and regulations. Make the necessary modifications as needed.
And...happy moneymaking inside Google AdSense guidelines.