1
general::
Phrase(s): finishing touch(s)
a final adjustment of something; some effort or action that completes something. • Norm is in his workshop putting the finishing touches on his latest project.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
A small change or addition that serves to complete something. For example, The room still needed a few finishing touches, such as a flower arrangement. This expression is sometimes put as a finishing stroke. [c. 1700]
American Heritage Idioms