finishing touch

(put /give) a finishing touch (to sth) AND (put / give) a finishing stroke (to sth) (a small change or addition that serves to complete something; the final move, the act that completes the task) -- делать последние штрихи, отделывать что-л.; шлифовать; завершать, доводить до конца;

give /put the final (или finishing) touch(es) to

Example 1:She applied eye shadow and lipstick and as a finishing touch, forced earring wires through the virtually grownover holes in her lobes.

Example 2:On Thursday afternoon Peadar Flaherty put the finishing touch to his redecoration: he installed a stereo radio and CD player.

Example 3:One day after the completion of an arduous and exhilarating task he had made for one of the miniature orchards a basket of brilliantly lifelike red-and-green apples, each no larger than the pit of a cherry, and as a finishing touch he had placed on the stem of one apple a perfectly reproduced copper fly--the maker of miniatures felt in himself a stirring of restlessness. (IN THE REIGN OF HARAD IV.)

see also
[lick into shape]
[work out all the bugs]
[lick into shape]
[tie up the loose ends]