Here's a lesson learned: pay close attention to any conference that offers a "First Pages" session. The Nieman Narrative Nonfiction Conference regularly offers this kind of session, and according to Sarah Wernick (who moderated Sunday morning's session), it's something borrowed from children's writers' conferences.
This is how it worked on Sunday. Attendees who planned to attend the session were invited to submit (in advance) the first pages from their narrative nonfiction projects. At the session eleven such first pages were read aloud (by readers specially present for the job--the pages were kept anonymous). After each page was read, the panel critiqued it. And the panel included two agents and two editors.
Hearing specific comments from each of the panelists on other people's work proved infinitely more valuable than any individual yet generic "this isn't for us...hope it finds a home with another agent/publisher" I've received to date.
If you want more details about this First Pages session (or maybe some guidance on how you might run a similar session at a conference yourself), click here.