Sizing typography mathematically provides an eye-pleasing structure that ad-hoc does not. The modularscale site is useful at finding the right one to use. I’ve included a link with my two favorites compared — Perfect Fifth and Golden Section 😀.
Mathematical Typography
I often find myself having to setup Sublime Text 3 on some new machine so I’ve gather all the plugins I usually use when building React ES6 code in a gist including some that are linked directly to a Github repo. 
Created With Flair 