Put all ingredients in a mason jar, place the cap on, and shake well. Store in an air tight container in your spice cabinet out of direct sunlight, until ready to use.
When ready to make a batch of ranch dressing, add 1/2 cup mayonnaise, 1/2 cup of sour cream, splash of milk, and 2-3 TBSP of the dry mix. Mix well and serve. Add more or less milk to make it the right consistency for what you need it for. I tend to do less milk for a veggie dip to keep the ranch thick and a little more milk for dressing to make it runnier.
Once you have a batch of ranch mixed up, store it in the fridge with a mason jar and lid for up to 2 weeks!