Following are the guidelines/best practices for effective test planning:

• Identify the requirements to be tested. All test cases shall be derived using the current Design Specification.

• Identify which particular test(s) you’re going to use to test each module.
• Review the test data and test cases to ensure that the unit has been thoroughly verified and that the test data and test cases are adequate to verify proper operation of the unit.
• Identify the expected results for each test.
• Document the test case configuration, test data, and expected results. This information shall be submitted via the on-line Test Case Design(TCD) and filed in the unit’s Software Development File(SDF). A successful Peer Technical Review baselines the TCD and initiates coding.
• Perform the test(s).
• Document the test data, test cases, and test configuration used during the testing process. This information shall be submitted via the on-line Unit/System Test Report(STR) and filed in the unit’s Software Development File(SDF).
• Successful unit testing is required before the unit is eligible for component integration/system testing.
• Unsuccessful testing requires a Program Trouble Report to be generated. This document shall describe the test case, the problem encountered, its possible cause, and the sequence of events that led to the problem. It shall be used as a basis for later technical analysis.
• Test documents and reports shall be submitted on-line. Any specifications to be reviewed, revised, or updated shall be handled immediately.
• Deliverables: Test Case Design, System/Unit Test Report, Problem Trouble Report(if any). 

Reference/Source: http://users.csc.calpoly.edu/~sroliver/csc405/test/swtplan1.html

Must Read – Test Plan Prep Guidelines – Part 1