Write down every amount that leaves for one month. Include cash, card purchases, automatic bills, and the small buys that feel too minor to count. Use a notebook, a spreadsheet, or the spending view in your bank. The tool matters less than finishing the month.
Then sort the lines into a few groups: housing, food, transport, bills, and everything else. Total each group. Most people find one or two groups that are larger than they expected. That is the useful part. You are looking for a pattern, not a perfect ledger.
Start this week
Download or print the last 30 days of transactions and highlight anything you do not remember buying. Those lines are your first candidates to cut.