We simply live within our means. We've never been foolish enough to get hooked into a lease for a vehicle, never pay interest on a vehicle purchase, and have had zero debt for decades.
We also rarely eat out which saves a huge amount of money. We take good care of our health (also saves a huge amount of money) and don't eat fast or processed foods; great for our health and saves money both up front and in health savings.
When we were younger, saving and investing for retirement were our first priority, and we never worried about having the latest and greatest gadgets or vehicles. We spent a total of just over 8 years paying mortgages on the homes we've owned, paying off the debt was another priority. We were able to take the money that many people pay on debt and interest and invest it, collecting interest rather than paying it.