01 - Cook macaroni according to package directions until al dente. Drain thoroughly and rinse under cold running water to stop cooking and prevent sticking. Set aside to cool completely.
02 - In a large mixing bowl, whisk together mayonnaise, sour cream (or Greek yogurt), lemon juice, Dijon mustard, garlic powder, salt, and pepper until fully combined and smooth.
03 - Add cooled macaroni, shrimp, celery, red bell pepper, red onion, and fresh herbs to the bowl with the dressing.
04 - Gently fold all ingredients together until evenly distributed and thoroughly coated with the dressing. Avoid overmixing to prevent breaking up the shrimp.
05 - Cover bowl and refrigerate for at least 1 hour to allow flavors to meld. Stir before serving and adjust seasoning with additional salt and pepper if desired.