The key point in this question is the focus of the first draft. The correct answer, C, emphasizes the importance of clearly expressing ideas and pursuing them actively, which is in line with the text's advice. Option A is incorrect because the text suggests that grammar can wait until the revision stage. Option B is wrong for the same reason as A, as punctuation and spelling are also secondary to idea expression. Option D is incorrect because the text advises against being constrained by the outline, which implies a flexible approach to structure.