I always wanted to add ads below post body because I believe readers will spent more time looking at the ads compare to that the content of sidebar. But to increase more revenue and engagement with our ads we can use these techniques to increase our income or CTR (Click Through Rate).
Look for
<div class='post-footer'><span class='post-labels'>and paste the code below above :
<b:if cond='data:blog.pageType == "item"'>Paste your parsed code here.</b:if>
Hope your problem solved. Happy Blogging!