I use BastilleBSD, it has a simple template system which I really like and decent docs. https://github.com/BastilleBSD/bastille

Bastille also has a sister project 'rocinante' which allows you to use Bastille templates on the host. I converted my ansible scripts to bastille templates and it works a lot better for *ME*. I found I spend more time updating ansible scripts whenever I needed to use them, it costed more time then just using a setup.sh script, which rocianate basically is. https://github.com/BastilleBSD/rocinante

Another new kid on the block for jails is AppJail, it has some interesting features. I have not played with it enough to say how stable it is. https://github.com/DtxdF/AppJail