01 - Cook the macaroni according to package instructions until al dente. Drain and rinse under cold water to stop cooking and prevent sticking. Set aside to cool completely.
02 - In a large bowl, whisk together mayonnaise, sour cream (or Greek yogurt), lemon juice, Dijon mustard, garlic powder, salt, and pepper until smooth and well combined.
03 - Add cooled macaroni, shrimp, celery, red bell pepper, red onion, and dill (or parsley) to the bowl with the dressing.
04 - Gently fold and toss until all ingredients are evenly coated with the creamy dressing. Avoid overmixing to prevent shrimp from breaking apart.
05 - Cover the bowl and refrigerate for at least 1 hour to allow flavors to meld. The salad tastes best when thoroughly chilled.
06 - Stir again before serving. Taste and adjust seasoning with additional salt or pepper if needed.