1 - Refuse to unit test because "you don't have enough time"
2 - Start unit testing and immediately start blogging about unit testing and TDD and how great they are and how everyone should do it
3 - Unit test everything - make private methods internal and abuse the InternalsVisibleTo attribute. Test getters and setters or else you won't get 100% code coverage
4 - Get fed with how brittle your unit tests are and start writing integration tests without realizing it.
5 - Discover a mocking framework and make heavy use of strict semantics
6 - Mock absolutely everything that can possibly be mocked
7 - Start writing effective unit tests