If you are monetizing your blog with Adsense or any other advertiser network then it is necessary to get clicks on your ads naturally. I am going to tell you about the placement of ads where they are most visible.
Try to put ads right after the post title, between post title and post content. This is the most noticeable place on the page.
Second most important and visible place is in the middle of content. If a reading a post so carefully then he will notice the ads in the middle of your post.
Try these tips and let me know if these worked for you or not?