my $rh_params = {
    scalar1 => $scalar1,
    scalar2 => $scalar2,
    list1   => \@list1,
    list2   => \@list2,
};

process_something($rh_params);

sub process_something
{
    my $rh_params = shift;
    my $scalar1 = $rh_params->{scalar1};
    my $scalar2 = $rh_params->{scalar2};
    my @list1 = @{$rh_params->{list1}};
    my @list2 = @{$rh_params->{list2}};
}