I think it's time i share with you guys a few things that has been working for me. My CTR is very good so this might be of help to some of you.
I disabled "Personalized Ads"
I use a responsive "link unit" directly after posts title and after post content with the following "Text & style":-
Border: 7ad03a
Title: 000000
Background: 7ad03a
I use a non-responsive "300x250" text/image ad unit after the second paragraph & before the last two paragraphs of my posts.
I make sure my ads are centered.
I have a custom sized ad unit at the header that performs extremely well but i won't be able to share with you guys the process on how i got that custom ad unit because it's a very technical process and you might mess up your site's design trying to do it.
Hope the little I've shared above will help some of you guys.