The goal of functional testing is to focus on individual functions, testing them one by one. Often this goal is difficult to achieve on it's own.
Possible Strategy:
- Create a function list (an outline of functions in the app or in the release)
- Initial function list can be an outline
- Becomes more fully-detailed over time (if this is your primary technique)
- Do this testing first before attempting more complex tests that involve several functions, might find blockers