My "Best Practices for Testing Tests"

• use Test::Tester
• use Test::Tester::Builder::Color during development if you have an output mismatch that you can't track down
• make liberal use of Test::* modules like Test::Warn, Test::NoWarnings
• use Devel::Cover to make sure that your testing modules have complete coverage
• if your code use]s [=strict, your tests should as well

Now go play.