When I work on my site I start jekyll using the following command line:

jekyll serve --future --drafts

I like this because it shows me what I’m working on and regenerates the files as things are updated:

Regenerating: 1 file(s) changed at 2016-05-22 14:24:25 ...done in 5.648222 seconds.
Regenerating: 1 file(s) changed at 2016-05-22 14:24:43 ...done in 5.055759 seconds.

The downside to this is that if I’m quickly switching between proof reading a post and editing a post it gets a little slow waiting 5+ seconds for the page to regenerate (you should try it). I started looking into the documentation for jekyll serve and there’s an option that allows you to limit how many posts it uses:

jekyll serve --limit_posts 50 --future --drafts

This cuts down the time required to see my changes:

Regenerating: 1 file(s) changed at 2016-05-22 14:25:29 ...done in 1.168727 seconds.
Regenerating: 1 file(s) changed at 2016-05-22 14:25:49 ...done in 0.96031 seconds.

That 4 seconds makes a huge difference.