I think where you get caught out is the yearly/every few months/every term expenses.
I was a single mum, and what I did was add my DD’s yearly expenses: school bus, DT supplies, school trips, non uniform days, school meals, haircuts, swimming lessons, uniforms etc, then divide the total amount to 12. It came to £100/month, and what I did was pay into a separate account named DD, on the day I got paid, £100. So every time there was a DD related expense, it would come from there.
I then had a budget for yearly expenses, house related: car and contents insurance, service, MOT, boiler service, etc, added that all up and divided to 12. Again, standing order, every month on the day I got paid, all in an account I named ‘Service’.
Another account for holidays. Which were mainly visiting family abroad, but still. I save 12% of my monthly income just for that. And I always buy my perfume, mascara etc abroad, either in duty free or in tax free countries, I cut my hair when I get to my holiday destination, it’s always cheaper. I also would have a facial and a massage when I’m there. In effect, I pay myself a 13th salary, feels like free money, and that’s where my clothes budget is too. Which are always bought in the January sales. Because I can’t quite shift that mindset of: anything I’d do for me is a luxury 😂.
I have a £1000/month budget for bills and mortgage, that’s another standing order in a separate account, and it includes overpaying the mortgage. £150 for food in another account.
So 2 days after I get paid, all my standing orders have gone out and I’m left I’m with a realistic amount of spare money. I work shifts, so the amount varies. I have a regular saver with FD that pays an interest of 7% and one with NatWest that pays 6%. I pay the maximum in those. Sometimes I get left with £30, others with £70. I bung the lot into a flex online saver, and that’s what pays for the occasional theatre ticket, my once a month pub meet up, a book I might want, a coffee with friends, birthday presents for friends etc.
For expensive months, like DD’s birthday or Christmas, I do overtime. I incorporate in this paying for Christmas parties, a new dress, more food etc. I do overtime in January, February and November.
Hope that helps. It’s a tedious and very controlled way of living, but when you’re on your own, you’re on your own.