Get any UNIQUE entertainment or games site. You will get more than 10,00,000 impressions per month. If you use php or other scripts, you can change ads placement very easily by making changes in few pages, which makes you get more CTR. But again that many number of impressions with php scripts makes u pay more for your server.
It's all about drawing visitors to your site(s). Posting on forums, promoting it through comments left, emailing people etc are all good ways to get visitors. Sometimes though you need to think of interesting ways to get visitors to your site. I tend to get visitors to my site these days through YouTube. If you have the right content and can make decent videos which people are interested in you can get thousands of extra visitors which means more Google impressions which will then mean more clicks! Earning with Adsense takes time. I started last November and only this month have reached my first $100. When I started out I would get perhaps 5 clicks per week, now I get about 5 per day. Personally, I now think the Internet is so competitive that to get all these visitors you really need something special on your site. Good luck.
get it indexed in major search engines and acquire more and more backlinks related to your site.If your site based on keyword health than search engines loves sites having back links with the sites related to health.