Once you design the type of budgeting spreadsheets you want to use, it will be easy to copy it for subsequent months or years. You can also use just one sheet and create tabs for each month.
You may want to create a workbook with multiple sheets for various aspects of your budget. You can have one sheet that keeps track of savings and investments and another sheet that lists your monthly bills.
The spreadsheet templates used for business purpose are also complex and these templates are used in stores and other business related affiliates. Profit and loss are mostly dealt with these spreadsheets. Invoice and other deposit related calculations also can be dealt with these spreadsheets.
You could make money doing something you love (or like [or maybe not so much but just really good at]). It's great to see a spreadsheet come together, and usually a lot better than what you originally envisioned. Especially when the dang thing works.
spreadsheet templates for small business
uses of spreadsheet