Deciding on the Next Novel

Since I don't write licensed fiction (yet!), I often get asked how I pick my next novel project. I'm currently working on my 12th novel length work and I'm continually finishing one and then moving onto the next. I've been in a pretty constant pattern like this since my second book, which turned out to be Lost at the Con. 

I'm not sure how usual that is. It usually takes me less than a week or too, sometimes as little as a day, for me to choose my next novel project.

I know some writers ta...