Tips and scripts can be found in Jekyll and Minimal Mistakes Goodies repo.
These are hacks I've made to the Minimal Mistakes, that I'll try to push to the main repo.
I replaced the Facebook by HN and Reddit share buttons. I more or less followed the guide from Minimal Mistake Layout doc. I could not find the $social list to update, so I used inline styles on the buttons to get the correct colors.
It would be better to add Reddit and HN buttons to buttons.scss