In a medium bowl, combine the mayonnaise, sour cream, and buttermilk. Whisk until the mixture is smooth and well combined, ensuring no lumps remain.
Add the dried parsley, garlic powder, onion powder, black pepper, salt, and Worcestershire sauce (if using) to the bowl. Continue whisking until all the seasonings are evenly distributed throughout the creamy base.
Taste the ranch and adjust seasonings as needed. If you prefer it tangier, add a touch more buttermilk. If you want it richer, a little more mayonnaise can be added. For more herb flavor, increase the parsley.
Once you're happy with the flavor and consistency, transfer the ranch dip to an airtight container. For the best flavor, refrigerate for at least 30 minutes to allow the flavors to meld together before serving.