Pre-paid stuff first. Pre-paid phone cards. Tabs at grocery stores. Put money under the counter on pay-day, got 'credit' in store. Wrote down everything in a book. Money in. Money out.
One of those shitty, high-interest rate bank cards later. The kind with no overdraft. Put groceries on it, paid it off end of the month, knew how much was on it. Took a while.