Unfortunately, you can’t do much to impact the residual value of your vehicle. It’s set by the lessor, so even keeping meticulous care of your car, which is usually required anyway by the terms of the lease, won’t keep this value up.
Car loans don’t use this phrase; it’s replaced by actual cash value. Actual cash value refers to the value of your car at any given time during a car loan. Most commonly, car insurance companies use this value to determine payouts if your car is totaled in an accident. Additionally, lenders may use the actual cash value if you want to get a cash-out refinance or you want to use your car as collateral for another loan.