1.Tester should develop the Test Cases that should cover each and every requirement
2. Should develop the TC's for all valid invalid expected and unexpected scenario's
3. The TC's should cover the entire application's functionality
4. Test Case is the document/idea through which user can analyze the whole application.
5. Test cases should be developed based on the Test Case standards and Test case template (like font size should be Arial 10 Test Case name should be short and descriptive should not contain spelling and grammatical mistakes etc)
6. Test cases should be in such way that any new user can understand and execute the application.