One of the first things to consider is what kind of data you have to work with in your cash flow template Excel spreadsheet. Ideally, you're looking for accurate monthly data including income statement items like revenue and operating expenses and balance sheet items like equipment purchases and cash from financing activities. If you have a longer time frame you can go with quarterly periods, but annual tends to be too long. After all, how can you predict what is going to happen beyond 5 years with any accuracy unless you're valuing an annuity?
In earlier times, accounting was done manually. With the coming of computers and increased technological advancement, accounting is slowly transferring from manual to mechanical dependence. It saves a lot of time. Earlier, hours were spent on drawing the basic design of sheets and other financial instruments. But now, you have access to balance sheet templates, which have readymade categories and spaces for computing. Now, one just has to enter the amounts manually and all other things are done mechanically.