1. Navigate to Reports > New Report > Forecast
2. Enter Report Title
3. Select the field you want to report on:
Metric = Forecast Amount
4. Select the format of the report:
Mark the radio button for Matrix.
5. Select how you want to subtotal the report:
Component = Entity
Field = Name (Grouped)
6. Select how you want to summarize data across columns:
Column = Month
7. Click More Customization button.
8. Under Edit Columns, add Forecast: Transaction Number.
Set Column Label = Order Number
Click <-Move button to position this column after Entity
Click on Forecast Amount (Weighted) column.
Set Column Label = Amount
9. Under Filters, add Forecast: Transaction Type equal to Sales Order, Invoice. Done. Add.
Note: This should give you a baseline custom report from which you can further enhance or modify to your business requirements. Your individual results may vary due to your accounting and financial configuration.