finishing touch(es)

The last detail added or change made to something to make it complete. Usually used in the plural. I don't want to spend much longer on this. Let's just add the finishing touches and get it ready for production. He's been putting the finishing touches on that painting for so long now, I'm starting to think he'll never be satisfied with it. You finally put the finishing touches on your thesis and handed it in? Oh, I'm so proud of you!

The final stroke(s) that ensure completion or perfection. The term is derived from painting, that is, the last stroke of the artist’s brush, and was soon transferred to any creative effort, ranging from cake-baking to assembling a costume. Its earliest appearance in print dates from the mid-eighteenth century, and Eric Partridge concluded it became a cliché within a hundred years.