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

1. **Thorough Requirements Gathering**: Spend time understanding the project requirements from all stakeholders to ensure clarity and completeness.
2. **Create a Detailed Project Plan**: Develop a comprehensive project plan that includes detailed timelines, task assignments, resource allocation, and budget estimations.
3. **Use Project Management Tools**: Invest in reliable project management software that can help in tracking tasks, dependencies, and progress.