To effectively manage the challenge of employing expert judgment in project estimation, consider the following best practices:

1. **Identify Relevant Experts**: Determine and engage experts with specific knowledge relevant to the project’s domain. This might include technical specialists, experienced project managers, or stakeholders with insights into similar projects.

2. **Facilitate Open Communication**: Create an environment where experts can freely share their thoughts and opinions. Encourage discussions, brainstorming sessions, and workshops to pool knowledge and insights.

3. **Diverse Perspectives**: Involve experts from various backgrounds and functions to capture a wider range of insights and avoid biases that may arise from a single perspective.

4. **Structured Processes**: Use structured methodologies for gathering expert opinions, such as Delphi Technique or nominal group technique, which can help in systematically reaching a consensus.

5. **Document Expert Input**: Keep detailed records of the expert judgments received. Documenting the reasoning behind their estimates helps in validating and refining future project estimates.

6. **Rely on Quantitative Measures**: When possible, combine qualitative expert input with quantitative data. Use metrics or historical performance to support expert opinions and provide a more reliable basis for estimates.

7. **Set Clear Guidelines**: Provide experts with clear guidelines on what assumptions should be made and what scope is being estimated. This will help in aligning their insights with project goals.

8. **Continuous Feedback Loop**: Create a feedback mechanism where experts can review and adjust their judgments as more information becomes available during the project lifecycle.

9. **Training and Development**: Regularly train and develop the skills of experts in estimation techniques and project management principles to enhance the quality of their input over time.

10. **Utilize Technology and Tools**: Leverage project management and estimation software that can integrate expert judgment while facilitating collaboration and data sharing.

By implementing these best practices, you can enhance the effectiveness of expert judgment in your project estimations, leading to more accurate and reliable budgeting and planning.