Most of my clients are in a similar industry and part of the world, so I’m able to keep it fairly consistent, but each client can customize it to an extent, like which KPIs they like to see in their data studio dashboard.
On the front page I have a small intro paragraph explaining what’s contained in the report, with a link to our glossary, FAQs, and contact, a chart illustrating a rolling 90 days traffic/conversion/cost volume, and a “monthly trend” snippet (something simple, like where we see budgets shifting overall in anticipation of coming seasonality). From there, a slide for each of the platforms being used with a breakdown of relevant overall metrics and a campaign-by-campaign summary. Each campaign type should get its own context, so the search portion emphasizes conversion and impression share, the social portion portion emphasizes reach, frequency, and engagement.
There’s no perfect method, but for me I like having that overall summary with all sources combined, then a breakdown of each in detail if they want it. Likewise with joining our monthly reviews, the clients are entitled to them, but they often don’t take us up on it, which is unfortunate. Some clients don’t read the report at all, some literally say the report is the thing they’re paying for, which I disagree with of course. The advertising is the thing you pay for, the report is like the receipt. If you want consultation, join the monthly reviews and talk to us, dangit.