It's common for a business to generate a monthly report with dozens of charts and tables that nobody actually reads closely. The problem usually isn't a lack of data, but that the report isn't designed to lead to any specific decision.
Start with the question, not the data
Before choosing what to include, it's worth asking what decisions will actually be made using that report: raise or lower ad spend? prioritise one channel over another? Every section of the report should directly answer one of those questions, rather than just showing a number because it's "available".
Always compare against something
A number on its own ("1,200 visits this month") doesn't say whether that's good or bad. Compared against the previous month, the same month last year, or a goal set in advance, that same number becomes meaningful and lets you decide.
Fewer charts, more written conclusions
A report with a clear sentence next to each chart ("paid traffic dropped 12%, likely because of this month's Google Ads price increase") is far more useful than a table with no comment at all, even if it has fewer visual elements.
Frequently asked questions
How long should a good monthly report be?
Usually shorter than it seems it needs to be: one or two pages with the key metrics and their conclusions usually deliver more value than a long document full of uninterpreted data.
Who should receive the monthly report?
Anyone with decision-making power over the business, not just whoever manages marketing. A report designed to drive decisions loses value if it's only read by someone who already knew that data beforehand.
Can generating these reports be automated?
The data-gathering part, yes, with tools like Looker Studio. The interpretation and conclusions are best left to a person who understands the business's context.