To manage inaccurate estimations in project budgeting, consider the following best practices:

1. **Use Historical Data**: Base your estimations on data from past projects that are similar in scope and scale. This can help improve accuracy.
2. **Engage Experts**: Involve team members and stakeholders with experience in the relevant areas to provide insights into realistic cost expectations.
3. **Break Down Costs**: Decompose project components into smaller tasks and estimate costs for each task individually, allowing for more accurate overall project cost estimation.