Going to sound insane, and it probably is.. But we don't budget, we have never budgeted, we have no idea how much money flows in or out.
But we do a real effort not to spend money.. We don't buy random crap all the time, we don't have subscriptions to anything but water, power, internet, cellphones and netflix.
We don't eat out. We buy food when they're on sale. We cook the food we buy, we eat the food we cook, we don't throw out food.
We don't live in expensive areas.
We own two homes (both paid in cash), we have never taken out a loan, we own two cars and have a son.
We live consistently below our means and have a surplus of capital every month. We don't earn amazing salaries.