TL;DR Use a short bash script to do deployment from your own computer directly to your *.github.io domain.
Why? So Yihui recommends using Netlify, or even Travis-CI in the Blogdown book. I wasn’t willing to setup a custom domain yet, and some of my posts involve a lot of personally created packages, etc, that I don’t want to debug installation on Travis. So, I wanted a simple script I could call on my laptop that would copy the /public directory to the repo for my github.
Manual Linking? Using blogdown for generating websites and blog-posts from Rmarkdown files with lots of inserted code and figures seems pretty awesome, but sometimes you want to include a figure manually, either because you want to generate something manually and convert it (say for going from SVG of lots of points to hi-res PNG), or because it is a figure from something else (like this figure from wikipedia).