I bought myself a static grass applicator about a year ago and started out by making grass on my layout. It was easy and fast, but the result was not very realistic. So... I tested, bought new grass and tested. Watched Youtube tutorials, read through forums and made new trials, until the result started to look good.
I made a short video tutorial communicating what I learned so far, so maybe if you´re thinking about start with static grass, this might be a short-cut to a better result from day one.