The fundamental rule of flag etiquette is: treat all flags with respect and common sense.
U.S. Flag Etiquette
The Stars and Stripes takes precedence over all other flags when flown within the United States. It should not be smaller than another flag flown with it. Other flags may, however, be flown the same height and in the same size. Other national flags should not be smaller nor flown lower than the Stars and Stripes when displayed together. If it is not possible to display two or more national flags at the same height, it is not proper to display them together at all.
The point of honor is on the extreme left from the standpoint of the observer ("the flag's right"). The order from left to right of flags flown together is: the Stars and Stripes, other national flags in alphabetical order, state flags, county and city flags, organizational flags, personal flag.
If one flag is at half-staff in mourning, other flags flown with it should be at half-staff. First raise the flags to their peak, then lower to half staff. The Stars and Stripes is raised first and lowered last.
A salute (hand over heart for those not in uniform) should be rendered when the flag is raised, lowered, or carried by on parade, when the national anthem is played (unless the flag is not present).
It is proper to fly the Stars and Stripes at night, but only if it is spotlighted.
No flag should be flown during weather that might damage it, based on a common sense interpretation of circumstances.
To extend the life of a flag, when it is torn it should be repaired and under no circumstances should a flag be folded while wet.
When a flag is no longer of dignified appearance and cannot be repaired, it should be destroyed in a dignified way (burned or sealed in a bag or box before being sent out for trash collection).
In a public gathering (lecture hall, church, etc.), the Stars and Stripes should be to the right of the speakers or on the wall behind them.
The canton of the flag (the blue 'field' with the 50 stars) should always be to the observers' left except:
The Stars and Stripes should be in the center of a group of flags only when:
It is not illegal or improper to fly any flag (state, ethnic group, organization, etc.) alone, but it is always preferable to display the Stars and Stripes at the same time.