How to Prevent Your Account Disabling

Pay attention!

• Useless to advise against any click on the ads on your own sites, as it's too common!
  
• The best you can do is to constantly watch the activity on your sites. There are also click-monitoring software that can automatically report any peculiarity (or generate a message through the internet client of the possible offender, who is ussually discouraged in such cases). Whenever you notice something out of the ordinary let AdSense™ know.
  
• Don't ever check your stats on any computer other than your own, and keep secrecy around your AdSense™ activity.
  
• If you suspect a certain static IP you can block it via .htaccess.
  
  
  • Filtering IPs via a .htaccess file seems a smart and logical step to take to prevent fraudulent activities from competitors
    
  • You can disable ads for your own IP to be safer.
    
• A very good measure would be to implement clicks limit (like 1-3 clicks from same IP for same ad a day).

When suspecting click fraud on your site, the first action advisable would be to temporarily disable the ads displaying on your site to prevent it from happening again and then reporting it to AdSense™.

Source: How to Prevent Your Account Disabling