How can I add an empty directory to a Git repository?

Question

How can I add an empty directory (that contains no files) to a Git repository?

Answer 1

An easy way to do this is by adding a .gitkeep file to the directory you wish to (currently) keep empty.

See this SOF answer for further info - which also explains why some people find the competing convention of adding a .gitignore file (as stated in many answers here) confusing.