It's been a while since I followed a recipe....
I heat up some milk with a couple cloves of pressed garlic, salt, pepper and nutmeg. (If using a Le Creuset-type baking pan it can be done right in the pan.) It should be strongly flavored. I fill the baking pan with sliced potatoes and the hot milk, adding more milk to come almost to the top, then drizzle the top with a little cream, and bake at 425* for an hour or so. Sometimes I layer in grated Swiss cheese--not too much--and sometimes not, depending on the rest of the menu.
That's it. I don't think there's a right or wrong way to do them.