a. Strictly follow the rules mentioned in Adsense policies. You will always earn more revenue from Adsense by playing it clean.

b. Never modify the Google Adsense HTML code. If have trouble embedding AdSense code in your WordPress or Blogger template, take help of the AdSense support forums or send an email to your AdSense account manager.

c. Never ask your friends or visitors to click on your Google ads. Google takes click fraud very seriously. Do not include incentives of any kind on your site for users to click on your ads. Don't label Google ads with text other than "sponsored links" or "advertisements.".

d. Don't click on your own ads - Google is much smarter than you think and can discover invalid clicks through IP addresses, site navigation patterns, etc. If you working on a new design for your site, avoid reloading your pages (with AdSense) excessively. You can turn off AdSense temporarily and avoid invalid CPM impressions. Or you can use the unofficial Google Adsense Sandbox Tool that is accessible from Firefox, IE and other browsers to see what kind of Google ads will be served based on content (website address URL) or keywords.

e. Don't place ads in pop-up windows, error pages or even empty pages. Update: With the new AdSense policy change, you can probably place ads on 404 pages. Check with the AdSense support team.

f. Don't start a "adsense asbestos" or "home equity loan rates" website merely to make money from accidental clicks. You will never make money out these Made for Adsense websites. Instead, write on topics what you are passionate about. Don't waste your money on high-paying adsense keywords lists. Stay away from AdSense Adwords arbitrage.

g. For short articles, CTR is best when ads are placed just above the content.

h. For long articles, CTR will improve if you place ads somewhere in middle of the content or just where the article ends - when visitors are done reading the article, they may be looking for related resources.

i. Use Text Ads instead of Image Ads as users get more options and the payout is often higher. If you still want to display image ads (for CPM), consider ad formats like the 300x250 medium rectangle or the 160x600 wide skyscraper as they support also support rich multimedia and the new gadget ads.

j. Google Ads with no background color and no borders will always perform better. Make the border color and background color same as your page background color.

k. Always put ads above the main fold. Make sure that the ad unit with the highest clickthrough rate is the first instance of the ad code that appears in your HTML source. Since the first ad unit is always filled before the rest, you want to make sure that ad unit is located in the best placement on your page.

l. Try setting the ad link URL color to a lighter shade. If your text is black, you may make the adlink as light gray or something like #666.

m. Go Wide - The large rectangle (336x280) is the best paying Adsense format especially for text ads. Try using the 336x280 large rectangle, 300x250 medium rectangle, or 160x600 wide skyscraper.

n. Don't places images next to Google ads as that will invite a permanent ban to your AdSense account.

o. Blend AdLinks with other navigation links or place horizontal adlinks at the top of your webpage. AdSense publishers are permitted to click on link unit topics on their web pages, provided that they do not click on any Google ads on the resulting page.

p. You should try adding a unit near the comments senction of your blog. See more AdSense tweaks.

q. You can put upto 3 adsense units on a page. Try putting a large skyscraper on the right navigation sidebar of your website. That area is close to the browser scrollbar. You can also add 2 AdSense for search boxes and 3 adlink units.

r. The first few lines of your content are an important factor for determining what Ads are served on your webpage. That's the right place to put keywords in bold (strong or &ltb> tags) or header tags (h1, h2, etc).

s. Always select the setting to open Google Adsense search box results in a new browser window, so you won't lose your visitors. Click the Open search results in a new browser window checkbox and this add target="google_window" to your form tag.

t. Maximum people think the search box is on the top right corner. So you know where to put it.

u. Always syndicate full text RSS feeds and then monetize your feeds with a 468x60 ad in RSS feeds.

v. Monitor the AdSense performance of individual web pages with Google Analytics

w. For low CTR pages, try changing titles or adding more relevant content to get better focused ads. Alse see: Get relevant Google Ads

x. Block low paying advertisers with Filters. Why to loose a visitor for an ad that will only pay you a cent. Use Overture or Google Adwords Keywords tool to discover keywords that are less popular with advertisers.

y. Learn how to implement AdSense Revenue sharing if you run a site with multiple authors and need to pay your writers based on advertising revenue generated from their articles.

z. Experiment with color schemes and layouts using split testing. You are the best judge when it comes to choosing ad formats for your own website.

Even Google doesn't offer the best advise always. For instance, in the visual heat map, Google suggests that webmasters are best served by positioning ads on the upper left-hand side of a Web page but if you go to any search page on Google, the ads the mostly in the right.
Bonus Tip: Use the AdSense Preview tool to determine what ad campaigns are currently targeted for your site in different geographic regions of the world.

Enter any keywords or a website address (URL) and choose a geographic location of the visitors to see all the related related Google Ads.