A good start would be a ban on ads based on who is viewing the ad vs what the content surrounding the ad is...

So, Casper mattress wants to have an ad spot in a podcast or a YouTube video in the video itself? That's ok.

YouTube wants to include an ad about a mattress in a video about home renovation? Also ok.

Stack overflow wants to show an ad for GitHub? Is ok to me.

YouTube wants to show an ad about Casper mattress based on whether someone has clicked on an ad about mattresses before? Banned!

This alone would be a great start.