To manage poor planning effectively, consider implementing the following best practices:

1. **Set Clear Objectives**: Define clear, measurable, and achievable project objectives. This helps ensure that everyone understands the project's goals and direction.

2. **Use a Project Management Framework**: Adopt a proven project management methodology (e.g., Agile, Waterfall, PRINCE2) that fits the nature of your project. This provides structure and processes to guide planning and execution.

3. **Involve Stakeholders**: Engage key stakeholders during the planning phase to gather input and ensure their needs are considered. This helps avoid misunderstandings later on.

4. **Develop a Comprehensive Project Plan**: Include detailed timelines, resource allocations, budgets, risk assessments, and task assignments. A well-thought-out plan serves as a roadmap for the project.

5. **Create Milestones and Deliverables**: Break down the project into smaller, manageable milestones and deliverables with specific deadlines. This facilitates tracking progress and makes it easier to identify potential issues early.

6. **Regularly Review and Adjust the Plan**: Conduct regular project reviews to assess progress and make necessary adjustments to the plan. This can help you respond to any changes or challenges that arise.

7. **Risk Management**: Identify potential risks early in the planning process and develop a risk management plan. This includes strategies for mitigating risks and addressing issues that may arise during the project.

8. **Train Your Team**: Ensure that your team is equipped with the necessary skills and tools to execute the project effectively. Training can help improve efficiency and performance.

9. **Utilize Project Management Tools**: Leverage project management software to help with planning, scheduling, collaboration, and tracking progress. Tools can enhance visibility and communication across the team.

Implementing these best practices can help mitigate the impacts of poor planning and increase the likelihood of project success. 

Would you like more information on any specific practice or tool?