How about a code generator which generates the code skeleton and the simplest tests?

You start with the project description:

{
  class => 'Foo::Bar',
  methods => [ 'x', 'y', 'z' ],
}
[download]

From this simple description you can generate:

• the directory tree (lib/Foo, lib/Foo/Bar, t, etc);
• a file called Bar.pm which the subs x, y and z;
• a test which tries to use the module, and check if it can do x, y and z.

Now you don't even have to write the tests!