package MyClass;

use Exporter;
use strict;
use vars qw/ @EXPORT @EXPORT_FAIL /;

@EXPORT = qw/ public_method /;
@EXPORT_FAIL = qw/ private_method /;


sub new {
   # bless reference ...
}

sub public_method {
   # ... do public stuff including calling private_method
}

sub private_method {
   # ... do stuff only class things should know
}