Trial and error is the only way I've had luck. Tedious and time consuming but eventually you will find what works for your website.
The ad placement is good-as I see it, you have two option: 1 - Split test different colors 2 - Make the site "less busy" - there is a lot going on and there are plenty of "distractions", so if you can make the ads stand out more be removing or moving the "distractions" your CTR will increase. This is another instance where it comes down to deciding whether you are willing to hinder the user experience to get more clicks.