A report can be mathematically correct, beautifully formatted, and still be useless.
Start With the Decision
What is management trying to understand? Profitability? Cash? Expense movement? Department performance? Variance?
Then Decide the Right Level of Detail
Too little detail hides the explanation. Too much detail buries it.
Trust Is Part of Usability
If the reader does not trust the totals, formatting does not matter.
Export and Distribution Matter Too
A report may need to print cleanly, export to Excel, distribute automatically, or feed a recurring management process.
The useful report is the one that fits the decision and the workflow around it.