I installed PDF-tools a few months ago and really like it. Their site has warnings about using it with macOS but the installation on a Mac is easy and it works perfectly. Recently, I have seen two posts that address PDF-tools. The first, by Ben Maughan over at Pragmatic Emacs, discusses setting it up on the Mac and a couple of tricks for making annotations to a PDF. If you’re an Ivy user, pay particular attention to his advice about mapping Ctrl+s back to isearch-forward when in pdf-view-mode because Swiper doesn’t work with PDFs.
Whereas Maughan’s post gives some hints for adding annotations to a PDF, Marcin Borkowski over at mbork.pl talks about ways to review and follow annotations already in a PDF. As Borkowski points out, that’s perfect for blending in changes to a paper from an editor or a reviewer but also useful anytime you’re working with collaborators and using PDFs as your lingua franca.
If you work with PDFs and are an Emacs user, you definitely should check out these two posts. They’re full of good ideas and are sure to improve your workflow.