I have used this with much success in the past:

sub foo {
    my $self = shift;
    my %args = @_;

    do_something() if $args{jam_on_it};
}
[download]

Have you considered, perhaps, using Params::Validate?

    my %args    = validate(@_, {
        search_text     => { type => SCALAR },
        my_customer_id  => { type => SCALAR },
    });
[download]

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

japhy,
When I am doing this without using an existing wheel, it usually looks something like:

sub thing {
    my $self = shift @_;
    croak "Incorrect number of arguments" if @_ % 2;
    my %arg = @_;
    for (@known_args) {
        # handle $arg{$_};
        delete $arg{$_};
    }
    if (keys %arg) {
        my $bad = join ' ', keys %arg;
        croak "The following args are invalid: $bad";
    }
    # ... remainder of thing
}
[download]

Cheers - L~R