In addition to working on my novels, I do freelance editing. I usually work on full novels, and my edits are generally comprehensive, meaning that in addition to editing dialogue and the writing itself, I evaluate characterization, motivation, pace, plot, and anything else I notice as I go along.
I'll always prefer working on my own novels, but I enjoy freelance editing and find it satisfying, especially when I submerse myself in the work. The author and I become a team. Of course the author is the team leader with the final say on everything, including which of my suggestions to embrace, modify, or ignore. I also welcome author input on the level of detail or depth of edit I provide. The novel is their creation. I never lose sight of that. My role on the team is to pick up on their goals and intent and work to make the novel as strong as it can be. It's a challenge, but a fun one, and I usually get completely wrapped up in the effort. Scenes continue to play out in my mind after I turn off my computer, sometimes even when I'm trying to sleep, occasionally when I am asleep. It's the same obsession that grips me when I work on my novels.
Now here comes the selective part. Because I get so involved, I'm picky about what I take on. In fact, recently declining jobs for full-novel edits is what prompted this blog entry. They looked like they'd be good novels, just not a genre or style that pulled me in. I need a strong connection to perform well over the long haul, and believe me, a comprehensive edit of a full novel is a long haul.
For me, there's really no choice but to be a selective editor. It's better for me and the authors.