To select the best test cases for your algorithm, you should follow some general principles and guidelines. You should use a combination of test case types, such as normal, boundary, invalid and random test cases. Additionally, you should use a representative sample of test cases that is neither too large nor too small. Additionally, you should use a systematic approach to generate test cases based on the input and output specifications, the expected behavior, and the possible edge cases of your algorithm. This can be done via techniques such as equivalence partitioning, boundary value analysis, error guessing, or random testing. Lastly, you should use a consistent template or format to document and organize your test cases. This includes the input, the expected output, the actual output, and the status (pass or fail) of each test case. Comments or descriptions can also be used to explain the purpose or rationale of each test case.