Combine in a food processor and blend into a powdery consistency.
Store in a container of choice.
To make ranch dressing:
Combine 1 tablespoon mix with 1 cup mayonnaise (I usually use 1/2 cup mayonnaise and 1/2 cup sour cream) and 1/2 cup milk.
Mix with wire whisk. Store in refrigerator until ready to use.
I do recommend making the dressing up several hours or a day ahead, so that all the flavors have a chance to blend together. Also, if you want a thicker or thinner dressing just adjust the amount of milk that you add in. Feel free to substitute yogurt, homemade mayo, or sour cream for the mayonnaise. You can also substitute soy milk or a different milk substitute for the milk.