It is the perfect dinner party dish because it looks and tastes wonderful, and you make it the day before. Making a really large one is a spectacular dessert for a crowd, simply double the recipie.
Use a vanilla pod if you have one - it tastes much nicer, but if not use vanilla Extract never Essence.
Another point to remember is not to over-heat the milk and cream, bring it just to the point where bubbles start to form at the sides of the pan.
Straining is important - otherwise you will not have a smooth custard.
Don't over whisk either - the aim is not to put air bubbles into the custard.