When should you consider creating a custom report?
You can't find an existing report that meets your needs.
You can't customize an existing report enough to suit your needs.
You can't find an appropriate contributed report.
Before creating a custom report, decide whether you want a list of transaction details or just a summary. For example, do you need a list of checks, paychecks, and bill payments that haven't been reconciled, or do you just need the total amount of uncleared items? If you need a list, create a custom transaction detail report. If you just want a summary, create a custom summary report.