I'm gonna wait for Steam version
Free work is ok if it's not-commercical project, such as modding for game. If it's commercical and they're going to make money off your work then it's unfair.
Aviral Agarwal and CGSociety have shared a quick guide to grooming hair with XGen in Maya. First, you start with some rough guides over your reference to better understand a hairstyle. What is the next step? Check out the guide to find out.
Here is a small piece to get you interested:
We will be using XGen’s Interactive Groomable Splines (IGS) to create our hair. We start with selecting a patch of faces that will make up our scalp to generate the hair description from.
In the hair description we will be changing the CV Count for the hair strands to 160 and rebuilding the strands. This is important so that the hair can handle the overall shape sculpting and modifiers we will be implementing later.
To give the groom its overall shape we need to sculpt some guide strands. To do that we add a Guide Modifier to the hair description. Let’s set the density of the guides to zero. Then using the Place tool which can be found in the description of the Guides modifier, we can add guide strands to our liking. These are then roughly sculpted following the guides we painted earlier in our reference to direct the generated hair and give its overall shape and volume. I am using the interactive grooming tools such as the Comb, Grab, Smoothing and Length predominantly for this process.
Next we add clumps using the clump modifier in a 3-tiered process. Namely Big, Medium and Fine clumps. They are in the order of increasing point density for the clumps. We layer clumps in such a manner as to give the hair groom a more natural structure/behavior.
You can find the full tutorial here.