Problems

Always have a catch-all.
If you're doing an if statement, always have an else.
If no actual need, then at least make a comment to that effect.
Can be left out if blatantly obvious, such as an if that dies.


  if ( something bad ) {
       die "something bad happened";
  }

  if ( test ) {
        ...
  } else {
        # do nothing
  }