Thank you very much. Class::Method::Modifiers does exactly what I want, but the bad thing is that you must know all the method names. I worked around this issue by using the special hash %PackageName::, but I really don't like this ugly fix. I looked briefly in the documentation of overload, but there doesn't seem to be any way to overload the method caller. Maybe, will come some day...

use 5.014;

package Foo {
    sub new { bless [] }

    use Class::Method::Modifiers qw(before);

    foreach my $method (keys %Foo::) {

        next if $method
            =~ /^(_|(?:BEGIN|new|before)\z)/;

        before $method => sub {
            my ($self) = @_;
            print "** Preparing...\n";
            push @{$self}, 'money';
            print "** Ready to continue...\n";
        };
    }

    sub Berlin {
        my $self = shift;
        print "> I'm in Berlin!\n";
    }

    sub Paris {
        my $self = shift;
        print "> I'm in Paris!\n";
    }

};

my $obj = Foo->new;
$obj->Berlin();
say "# Self contains: @{$obj}";
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