Another variant which I overlooked to often is if you have a construct which returns an error but does not exit the script later move it in a function and now it does exit the script.

  set -e
  [[ 0 == 1 ]] && true
  echo Status: $?

will print "Status: 1" but

  set -e
  func() {
    [[ 0 == 1 ]] && true
  }
  func
  echo Status: $?

will print nothing but exit after func returns.