Create an objective-to-evidence table
For each objective, record the population or source material, the information needed, the method of collection and the intended analysis. If a row cannot be completed coherently, revise the objective or the method before proceeding.
Identify assumptions and constraints
List access, recruitment, equipment, measurement and timing constraints. Distinguish what is known from what needs pilot work. Sample-size decisions should be justified for the objective and assumptions, with specialist input where required.
Plan how deviations will be handled
Explain how missing observations, exclusions, protocol changes and unexpected practical problems will be recorded. Define primary questions and exploratory work in advance where appropriate. A transparent record is more useful than retrofitting the method to the most attractive result.
Review the plan with the right decision maker
Take the table, assumptions and unresolved questions to your supervisor or project team. Obtain required approvals before relevant research activities begin. Keep a dated version and describe later changes accurately in the final methods section.