I'm a peer reviewer for the AICP application process. I've looked at a couple hundred applications at this point. My best advice is to systematically follow the candidate guide for your responses to the three criteria. Focus on your role. Don't overthink your responses. Don't make assumptions that we have any knowledge of the project or process you are describing, because we don't work at your employer. Be direct in your responses.
One common mistake I've seen: candidates think they need to use different examples for each criterion. You can use the same example, just discussing different aspects of it. You could easily have a single example that allows you to discuss how you applied a planning process appropriate to a situation, allows you to demonstrate employment of a comprehensive point of view (remember, not just that you were comprehensive, but how use of a comprehensive point of view affected outcomes), and allows you to demonstrate how you influenced public decision making in the public interest. It doesn't have to be a fancy example, either. Some of the best responses I've reviewed have essentially been everyday zoning change requests.
EDIT: Skip the fluffy prose language in your response. Put your brain in "technical memo" mode like you would a staff report. Also, by and large, we do not care what other people in your department were doing unless it is specifically relevant to your response. I once reviewed a response in which 1-2 sentences described the AICP applicant's role, and the rest of the rambling 400+ word response talked about what everyone else in the department was doing on the project.