Displaying our national symbol is actually mandated by an official Flag Code. For instance, the flag should not be flown in the dark or inclement weather. It should not be used as decoration – that’s a job for bunting, streamers and decorative materials. Always display the blue part on top. When the flag is lowered, it should never touch the ground or any other objects, it should be gathered by waiting hands and arms, respectfully and ceremoniously folded (ask a veteran how). Flags should be mended and cleaned when needed – we clean American flags at no charge as a courtesy year round.
From:: Flag etiquette.