Last weekend, I had to edit the galley for the July print release of our Samhain title, Craving Kismet. Pepper and I wrote CK in August 2006, and it was the second professional title we wrote together. It didn't get released in e-book until 9/07, however, due to our editor leaving at Samhain and our release getting delayed. But in reviewing the galley, I learned one thing.
Pepper and I have come a long way in a year and a half.
Any writer worth her salt will learn with each publication. Editors are wonderful for this. Going through the editorial process, you are exposed to all your flaws in all their glory. The more you do it, the more you see them. The trick, then, is to learn from those. Take what you did wrong and fix it - or at least try to improve it - while you're writing the next manuscript. Not when you're in editing. When you're actually writing. Do this over and over and over, because honestly, you will never be perfect. There will always be something to learn.
When there's two of you, that means you're both bringing unique flaws and crutches to the table. While a second set of eyes might be able to point them out, they might also be blind to them. There are a lot of things in CK I wish I could change, because Pepper and I have strengthened our skills to overcome some weaker elements in our writing. We've also learned what words we favor. For instance, in a lot of our early stories, our characters murmur. A lot. As a result of being exposed to that repetition, we've learned to be far more frugal with our dialog tags.
If we didn't try and take something new from each editorial experience, we'd stagnate, and really, nobody wants that. We always want our work to get better. So don't be fooled into thinking having another person there means you improve twice as fast. But it does mean you don't have to learn how to do so alone.