The people I work with are usually having trouble writing (which goes without saying, I guess).
One way to get writing moving is to get feedback. But feedback can be tricky; in particular giving work to professors can often result in very painful feedback. And, in general, getting feedback is to open oneself to rejection.
This can create negative emotional states in a writer, and can lead to writer's block.
Part of my strategy to assist people is to create a solid, positive feedback loop which is still able to effectively critique work and guide efforts in the improvement of that work. This can include discussion of how to respond to my feedback, and what is intended by my feedback, and general purposes of feedback, as well as ways of responding to criticism.
One reason for this is to help the reader find a space in the project where negative emotional energy does not gather, and therefore the writer feels safe submitting work to me, which allows me to work as an editor.
Another reason for this is to provide the writer with a model for responding to criticism that can be applied when criticism is less carefully planned. Or even if it gets nasty.
This is not just a process of saying only nice things about a work; if I don't challenge the weaknesses of a work, I lose the opportunity to guide the writer's effort to the areas where that effort will be most efficient, and it's generally harder to improve on what is already strong than it is to improve on what is weak--you can always (or at least) delete a weak section, thereby improving a work as a whole.
This is a crucial skill for a writer: to be able to use editorial critique in an effective manner, to be able to distinguish the important critiques from the mean spirited attacks, and to be able to distinguish which critiques are on the mark, which just slightly off the mark, and which are off target.
One way to think about feedback is as the response of a reader--if you don't like the response you got, then you know that you want to modify what you've written to change the response.