Brief
I have created for multiple organisations, a set of data visualisation style guidelines and templates across spreadsheets, Tableau, Power BI, and presentation software that extends corporate branding guidelines in a way that is suitable for presenting data clearly and effectively.
Solutions
The spreadsheet Power BI / Tableau guidelines generally cover how to best present
Performance headlines
Various kinds of bar charts and line charts
Specialist charts such as waterfalls and Sankeys
Fonts, colours and sizing
Effective labelling
Google slides or Powerpoint guidelines generally cover
How to structure a compelling data presentation
Some options for clear layouts
How and where to place commentary
Colours, fonts, spacing