What do you do if your characters want to try something you're not sure is humanly possible? A feasibility check, that's what. Like when my mc decided (well, not so much "decided" as, um, had the decision thrust upon her) to take a ride on a trebuchet, I needed to know if this would be believable. Not being the thrill-seeking sort (yes, when it comes to my physical safety, I am a cautious soul, otherwise known as a "wuss" or a "weenie"), I let my fingers do the clicking. Came upon this video on YouTube:
Yay! My scene was in the realm of credibility.
This You-searching technique also comes in handy if your characters decide they have to visit someplace you've never been to, and aren't likely to get to before your book is complete. Almost anyplace in the world you can think of, some tourist has been there before you. And made a vid. And supplied it with excruciatingly detailed commentary. Or, if you're lucky, just set it to background music:
Ditto for things you'd like to use to add flavor to your narrative, but suspect they may be too silly to be realistic. Trust me, this is not likely. Say your book is set in a circus, and you need to know if elephants can roller skate. Ta-da:
See? Perfect! One caveat, though: once you travel down the You-searching path, your actual writing time may suffer. It's addictive.