I use an A4 pad. I record each individual amount collected on one page (actually about six sheets per month), and one page for expenses, the latter being recorded as follows:
Date Payee MVE Wages Insurance Consumables Stationery
MVE = Motor vehicle expenses (I claim at mileage rates)
Consumables = replacement materials + sustenance etc
I keep all receipts where available, in date order.
If done every day, it takes next to no time to keep up to date.
John.