Scallops start to turn rubbery if you wait too long to serve them, so get them on the plate right away. And be sure to serve them with the beautiful caramel-colored crust facing up!
If you like, you can melt a bit more butter in the pan and drizzle it across the scallops right before service. A simple beurre blanc sauce is a great accompaniment for scallops. For more sauce ideas, here's a list of sauces for fish and seafood.