Wash and peel the potatoes, then cut them into 1-inch cubes. Place the cubed potatoes in a large pot and cover with cold, salted water; bring to a boil and cook until fork-tender, about 15-20 minutes.

While the potatoes are cooking, prepare the dressing by whisking together mayonnaise, Dijon mustard, apple cider vinegar, salt, and pepper in a large bowl. Stir in the chopped celery, diced red onion, and fresh dill.

Once the potatoes are cooked, drain them thoroughly and let them cool for a few minutes; do not rinse them. Gently add the warm potatoes to the dressing, stirring to coat evenly.

Secret #1: Dress the potatoes while they are still warm to absorb the flavors better. This allows the dressing to infuse into the potatoes, resulting in a more flavorful salad.

Secret #2: Use a combination of mayonnaise and a touch of apple cider vinegar for a balanced, tangy dressing. The vinegar brightens the richness of the mayonnaise.

Secret #3: Incorporate fresh herbs like dill at the end for a burst of freshness. This adds a vibrant aroma and taste to the finished dish.

Taste the potato salad and adjust seasonings as needed, adding more salt or pepper if desired. Cover the bowl and refrigerate for at least 1 hour before serving to allow the flavors to meld.