If it is at all possible, you should absolutely make this dressing in advance. It will reach the peak of its flavor perfection if you let it sit at least 8-12 hours.However, if you can't let it sit, it will taste fine and you won't be sad.
I like to make my homemade dressings in mason jars. It's easy to pour everything into the jar, put on a lid and ring, and shake it until it's well blended. You can even get a pour spout to make using the dressing directly from the jar easy.