Going off the last post, I will also say that find value in becoming slightly jaded to the footage. I always note my initial reaction to the most powerful footage and remember the audience will likely also have a strong initial reaction, but it's also important to remain rigorous about making the scene work so that it is serving the piece as a whole and not just in there for the sake of it being highly emotional. With a slightly jaded perception, I find that I have to try that much harder to be impressed again with the way the footage plays into the whole film.
It can be a little manic of a process, but being able to see the footage through a lens of radical acceptance and then flip to a lens of harsh criticism, has allowed me in the past to see a more nuanced view of any given clip's limitations – and its potential.