How do you guys find plot holes in your stories? I'm unsure how to approach this. I want to keep my eyes out for plot holes as I work through the outline. I'm working on a series of six books. The series is split into two sections because Book #1-3's main character is different from Book #4-6 (main character's kid), but the events of #1-3 are linked to #4-6 indirectly (this isn't revealed until at some point in Book #4-6).

Sorry. I'm babbling.

But yes, plot holes. How do you find them?