One problem with many speech endings is the ending. Many speakers seem to focus their attention on either the opening or the main body of the speech and leave the ending as an afterthought.
One of the important reasons speakers start with the ending in mind first is that it allows you, the speaker, to have a roadmap of where you want your audience to go. Most speakers want their audience to do or feel something when they leave the room. There has to be a plan for this in the main body of the speech. This leads to the ending that you want to happen.
One great way to help the entire speech is to build a map and plan everything from start to finish. Also include in this map what you want your audiences to feel. All of this planning will lead to a great and memorable ending.