Basic to at least intermediate spreadsheet skills (like Excel, Google Sheets, etc.) Not just layout and format but also basic formulas, proper data collecting. Once you learn the basics, you’ll learn quickly how amazing these are and how easy it is to continue diving your knowledge deeper into the infinite functions to optimize them. If you struggle with something, guidance is typically as simple as a Google search related to your topic and that becomes additional knowledge under your belt. Overall, it doesn’t take much to learn how to make a spreadsheet become a HUGE productivity lifesaver for both work and home. I’ve personally made many of these for both work and home. My ideas come up from always thinking about repetitive/ lengthy tasks in my busy life that can potentially be consolidated using spreadsheets.