When you take it down, don’t just wad it up like a used napkin. That’s a sign of flag abuse. Fold it neatly. The official method is a bit of a puzzle: fold it in half lengthwise, then into triangles until you get a neat blue-and-white bundle. But if you’re in a hurry, just fold it into a rectangle and hide it in a drawer. Nobody checks your folding.
If you do want to impress someone, make sure the red and white crosses end up on the outside of the fold. That way, when you open it next time, it looks like you know what you’re doing. And always store it in a dry place. A damp flag smells like a wet dog wearing a crown. Not a great combo.