You can simplify your code without sacrificing clarity like this:

sub foo {
  my $hash_ref = shift;
  print "$_\n" for values %$hash_ref;
}
[download]

If you want to use both keys and values, you still can do it with a single loop:

sub foo {
  my $hash_ref = shift;
  while ( my ( $key, $val ) = each %$hash_ref ) {
    # do something with $key and $val
  }
}
[download]