Talk to reporters before they go on assignment. Make the story clearer and more precise on story skeds. Talking in advance can give the reporter a sharper focus on the story and a better idea of people they should interview. Interview reporters after they return from stories. It really should just be a conversation.
Reporters generally like to talk about their stories to gauge interest before they begin writing.
Care about the story. Lack of interest can dull a reporter's interest in her own story. Ask reporters to tell you in 30 words or less what the story is about and what it means to readers. Don't look over reporters' shoulders while they work or snoop in their computer files. The time to coach is before the reporter begins the assignment and after the information is gathered.