1: Pour 200 ml liquid cream into a bowl, add 20 g vanilla sugar, mix well and put in the freezer for 15 minutes.
2: Maybe you'll see a ring of frozen cream all around the inside of the bowl; that's good news, meaning that your cream is at the right temperature.
3: Remove bowl from the freezer and without delay, whip cream at high spped. It becomes firm in about 2 or 3 minutes, 5 minutes maximum.
4: Continue to whip until the cream is firm enough, not too much otherwise you will make butter. Your Chantilly cream is ready.
5: Chantilly cream can be made with a gourmet whip, see how in this video.
Remarks
There's a well known little story which says that Vattel, chef to the prince of Condé, invented Chantilly cream for a party gave by his master for king Louis XIV. There is a lovely scene about it in the Roland Joffé movie "Vattel". It's well told, probably fictionalized, and quite hare-brained ("it's the sugar that makes the cream smooth"). Following the same ideas it is possible to make chocolate chantilly and foie gras chantilly.