I have a long /etc/host file with many of the worst tracking/ad services that i have found.
Blocks of a very large portion of the stuff that i do not like.
The upside here is it becomes an effective adblock for iOS when on the local network. I'm not sure how to extend this so that it will work when my iPhone is on an LTE network.
Was probably a year since i last touched it, so it could probably use some updating.
Good tool for adding lists to your hosts file.