A writer friend I've known for nearly two decades sends sections of her manuscript to me every few weeks, and I send mine to her in Virginia. Every Tuesday evening we talk on the phone. Part of the time we just catch up as friends; part of it we spend giving each other feedback on our work in progress.
Now that I'm into the next phase of revision on Judith I am discovering the value of that exchange, and every other criticism group I've belonged to since I started writing. Just one remark my writing partner made weeks ago, jotted in the margin of Chapter Three, has deepened the tension of the story as a whole.
While on vacation I met an author doing a booksigning. She and I chatted for fifteen or twenty minutes. She very kindly made several suggestions that are changing the way I see writing, revision--and promotion.
Let me just say I am so very grateful for the friendship of other writers.