How to remove .DS_Store from command-line auto-completion using cd?
export FIGNORE=DS_Store works for me.

The GNU Bash manual provides extensive information on programmable completion.

Specifically, from the documentation on bash variables


  FIGNORE [is a] colon-separated list of suffixes to ignore when performing
  filename completion. A file name whose suffix matches one of the
  entries in FIGNORE is excluded from the list of matched file names. A
  sample value is ‘.o:~’


If you are concerned that there might be existing suffixes in FIGNORE, then you can use:

export FIGNORE=$FIGNORE:DS_Store