My husband and I always felt like we had extra money in our bank account that we could use to pay down debt. We'd make the extra payment and then we'd be short and have to use our buffer to make ends meet through the end of the month.
I developed a spreadsheet that took into consideration the due dates, frequency, and amounts of each of our budgeted items. With this I built a forecast of our daily cash flow that would predict from our current bank account balance. With the forecast, I could now easily see when we had extra money during the month, how much extra money at any point, and the impact of making the extra payment.
This was the start of what is now Bulent.