Pinky, if you're talking about LEED-NC v2.2, this is not a question of maintaining your certification. Once awarded, only the LEED-EBOM certifiation needs to be maintained.
The examples you are giving are more about following through on promises made during the LEED-NC certification process. There may also be additional examples—maintaining preferred parking, and following through on commissioning requirements, for example.
The project's LEED documentation should have included plans for how these processes would be implemented. The building owner and others involved should be making a good-faith effort to follow through on those plans.
Back to your question—you asked 'how do you ensure." A key part of this question is "you"—what role are you in relative to the LEED project? The answer to your question will vary depending on your role.