I feel like this post is a bit Dr Seuss--One fish, two fish, red fish, blue fish.
Once I had a bestselling author explain to me that he can't write and promote books at the same time. For him, writing required the creative side of his brain where promoting (marketing) required the more analytical, businesslike side. I'm not a bestselling author by any stretch of the imagination, but I totally understand what he means.
For me, it's writing and editing.
Drafting that first pass of any manuscript requires you to let loose your creative side, to plot, dream, challenge, and grow that part of your brain.
Editing, however, requires a more detached, analytical view of your work. You can't afford to LOVE it while you're trying to FIX it. Some things have to change; others need to be ditched completely.
This month I have divided my time up between writing and editing. Between working on edits for one book as I get them back from my editor, I'm working on the first draft of another book. And it's HARD. I find myself trying to draft while having a serious plot block (like a writer's block, but with the plot--not knowing what comes next), or going back through what I've already written to answer a question--like what is the character wearing--and wanting to edit it as I go. It takes an extreme sense of control to not give in to the impulse. Yes, I'm still working on it.
Yesterday I had an awesome breakthrough about my plot problem and I'm so excited to charge right through the current block.
Who's willing to bet that tomorrow I get another round of edits back for the other book? :)