What seems to be most important aspect of a PR plan?
Clear definition of goals for the plan. Who, what, when, where: Identify target audience(s) and objectives. List of key communication tactics and venues. Cost/budget.
Which marketing concepts may especially apply to effective PR campaigns?
If you know how to position your product/brand to have an emotional impact with your target audience, you are creating a relationship that flows both ways. You can adjust your PR campaigne to further engage your audience based on their feedback. Remember cost, customer value, convenience, communication.
If you are taking on your own PR campaign now or in future, please share any aspects of the planning process.
Thoroughly research the topic. Consult stakeholders to gain insight and buy-in. May take extra time but buy-in is good PR. Develop a detailed plan keeping in mine the 4 w’s: who, what, when, where. I would develop a schedule for the project and a budget ±. The plan will clearly state the challenge, desired outcome(s), targeted audience and desired messages, communication strategy/tactics/venues. Once the plan is presented and approved, it must remain consistent as possible throughout…a moving target is difficult to hit!