I always make my potato salad a day ahead. I think it gives the potatoes time to absorb the flavor of the dressing. For the same reason, I try to mix the potatoes and dressing together while the potatoes are still slightly warm from cooking. I think potato salad actually tastes better the next day.....and the next and the next and the next!! So cook ahead so you can enjoy your party tomorrow!
"Here's a secret: Good cooks make mistakes all the time. They take wrong turns and end up in strange places." Chef Daniel Patterson