One problem that speech writers have is writing the perfect ending. Many times writers are stuck in a circle, wanting perfection but never coming close.
One great way to avoid all of this is to follow the 80/20 rule. Write till you have completed eighty percent of what you are trying to accomplish. Stop and wait a few days. Come back later with fresh eyes and look at what you have written and then you can then decide if you need to work on the remaining twenty percent.
There will be times you will feel no need to work on the remaining twenty percent because you like what you have written. Other times you will want to work on the remaining twenty percent because you know that something is missing. Again, you will only complete eighty percent and stop.
The result is that you get things accomplished with less headache and a feeling of accomplishment.