We went with a timeless "X" pattern when building these simple yet affordable exterior DIY window shutters. With a little math, DIYers of any skill level can build these shutters. These are the steps for how to how to build exterior wood window shutters, plus the tools and materials you'll need. We built these shutters out of shiplap, primed, and then painted with "Field Trip by Clare Paint". These outdoor shutters took less than a day to assemble and paint. And DIYing them saved us…