You end a summary with the conclusion of the article or a comment about the reason the author has written this piece. Here are some examples:
1. In conclusion, the article clearly articulates all of the reasons a person needs to be careful not to let their car battery freeze in winter.
2. To make sure the reader gets the point, the author concludes with a funny story of why she will never wave to a policemen at the side of the road again.
3. Although she may belabor the point too much, Johnson does clearly and effectively explain many reasons why college students should take the time to recycle as much as they can.