Here’s a forehead-slapper that almost nobody does—but every angler should.

When you fish into a glare and the water surface has that silvery look to it, even through polarized lenses, use a dry fly with a black post. But when the sun is behind you and the water has a flat finish, use the more common white-post fly. The difference is dramatic, and you’ll hook more fish by better recognizing eats.

You can use a Sharpie to turn posts black, or some fly shops, such as Dan Bailey’s, carry black post flies.