How do I choose a package name for a custom Perl module that does not collide with builtin or CPAN packages names?

Question

I have read the perldoc on modules, but I don\'t see a recommendation on naming a package so it won\'t collide with builtin or CPAN module/package names.

In the past

Answer 1

What's wrong with just picking a name for your package that you like and then googling "perl the-name-you-picked"?