Keeping a simple event budget spreadsheet
Launch library · evergreen read

A basic spreadsheet, tracking expected costs against actual spending as an event comes together, gives an organiser a genuinely clear, real time picture of where things stand financially, rather than relying on a rough mental estimate that tends to drift considerably as small purchases quietly accumulate across weeks of planning.
Separating fixed costs, such as venue hire, from variable ones, such as catering that scales with final numbers, makes the whole spreadsheet far more useful for genuine decision making as an event approaches. This simple structure also makes it considerably easier to spot where a budget is quietly slipping off track.
Updating the spreadsheet consistently, rather than only when a problem is suspected, catches issues while there is still real time to adjust the plan sensibly. A shared, transparent spreadsheet also helps a small committee stay genuinely aligned on the numbers rather than relying on one person's private, unshared memory alone.