Beta Testing: When's the Right Time to Bring in Outside Readers?

The most current draft of Secernere has been re-written three times, then line edited twice, and I've read the entire thing out loud to myself. But I know it's not quite done yet. I can feel it. I also know I am too close to the manuscript at this point to see the flaws a fresh reader will catch immediately. That's why I enlisted beta readers—and why you should too. But it's essential to bring them in at the right point in the process.

My first betas were ill-chosen. Do not ask your...