FAQs on flying the US flag at half-mast
How to fly your flag at Half Staff depends on what sort of flag pole you are using
When raising the flag to half staff on a vertical pole, always raise it briskly to the top of the flagpole for a moment before lowering it. When taking it down for the night, raise it to the top of the flagpole again & lower it to the bottom.
With a telescoping flag pole it is acceptable to put the USA flag on the second set of rings instead of the top set. In this case the top set would be left empty.
When the United States flag is flown at half-staff, State & other flags should be removed or flown at half-staff too.
For flags that can’t be lowered, such as those on many homes including our historic Bidwell-Wood House, the American Legion says that attaching a black ribbon or streamer to the top of the flag is an acceptable alternative. The ribbon should be the same width as a stripe on the flag and the same length as the flag.
Photo from here.