i have a really cute red and black plaid high waisted pencil skirt with a black blouse and some pearls to dress it up. I did a bit more dramatic makeup than they were used to seeing look like at my office. oh and i wore opaque black tights.
Another year I found a really cute simple cocktail dress that wasn't too fancy nor too revealing it worked and i brought a dressy sweater luckily bc it was cold at the restaurant.