Unattended Linux Mint Install

I am trying to create a Linux Mint 17.1 development box (in a virtual machine) but I'd like to automate the process.

The instructions on how to perform an unattended installation are pretty out of date:

http://ift.tt/1paSKxf

I've had no success using a preseed.cfg file. I would usually get stuck at some part of the Ubiquity install screen.

I was wondering if anyone has had any success in bringing up a Linux Mint VM or if there's someway of figuring out how to determine what values to put into the preseed.cfg file so that a fully automated installation can be achieved.