I do a zero based budget so I work out exactly what comes in per month and then split it.
It looks something like this
Rent+bills = £908
Food 100 (I do 2 shops a months of £50)
Petrol 40
Child’s envelope 40
Car maintenance/insurance envelope 40
Miscellaneous envelope 80
Holiday fund 200
Then whatever I have left goes to long term savings (house deposit) which is usually 400/500
Therefore the only money I can spend (on no essentials) is from miscellaneous but I hardly use it tbh. We are minimalists so don’t spend regularly. We tend to save up and buy quality items that we have waited a while for so we know we definitely want them
This idea may sound restrictive but to me it’s the opposite. I have my money exactly where it needs to be for future purchases. My car insurance money is always waiting there to be paid in full. If my child needs new shoes the envelope is there waiting. It’s not for everyone but I’d never change back
Plus we always have money waiting for holidays!