If you are just starting this tradition, or prefer to keep things simple, you can stick to some dollar store snow blankets and the houses. It will look wonderful and fill you with Christmas spirit.
But having grown up with a father who worked on model train sets (and having made a couple of my own platforms in my youth, right down to paper-maché mountains and tunnels), I know it's the little things that really bring a village to life. Props of various types: trees, people, a skating rink, a bridge or two, maybe a backdrop...
... and of course, a train.
I have two train sets (a Thomas Kincade one from my Dad and a standard HO set), two motorized trolleys and and a simple prop trolley with no motor.
A train or trolley adds that bit of animation - that life - to the static village.
I don't always have the room to set up a full oval or circle for the train, but one of my trolleys comes with specially designed tracks that allow it to auto-reverse on the track. This is great for narrow displays like bookshelves, mantels, etc. I use this trolley almost every year.