Combine all ingredients in a bowl. Use immediately or store in an air-tight container until ready to use.
To Make Ranch Dressing: Combine the ranch seasoning mix with ¼ cup mayonnaise, ¼ cup sour cream, and ¼ cup milk. Whisk until smooth.
To Make Chip Dip: Combine the ranch seasoning mix with 1 cup sour cream and stir until smooth. Let the dip sit for about 10 minutes to allow the flavors to blend.
