my $first;
my $second;
my $third;

sub First  { ... }
sub Second { ... }
sub Third  { ... }

{
   $first  = First();
   $second = Second();
   $third  = Third();
}

##</code><code>##

sub First  {                          ... }
sub Second { our $first;              ... }
sub Third  { our $first; our $second; ... }

{
   local our $first  = First();
   local our $second = Second();
   local our $third  = Third();
}

##</code><code>##

our $first;
our $second;
our $third;

sub First  { ... }
sub Second { ... }
sub Third  { ... }

{
   local $first  = First();
   local $second = Second();
   local $third  = Third();
}

##</code><code>##

sub First  { ... }
sub Second { ... }
sub Third  { ... }

{
   my $o = ...;
   $o->First();
   $o->Second();
   $o->Third();
}

##</code><code>##

sub First  { ... }
sub Second { ... }
sub Third  { ... }

{
   my %h;
   First(\%h);
   Second(\%h);
   Third(\%h);
}