Some energy transfers are unwanted. In a machine, energy is wasted by friction between moving parts. In a house, energy is wasted when thermal energy escapes to the outside. We can reduce both.
Lubrication means putting a layer of oil or grease between moving surfaces. The lubricant keeps the surfaces apart, so there is less friction. With less friction there is less heating, so less energy is dissipated and more is transferred to the useful output. Oiling a bicycle chain is an everyday example.
Thermal insulation reduces the rate at which thermal energy is transferred. Materials such as loft insulation, foam in cavity walls and double glazing contain trapped air, which is a poor thermal conductor. A hot water tank can have a lagging jacket. These slow the escape of energy by conduction and convection, so a building stays warm for longer.
Other ways to cut unwanted transfers include using smooth bearings and streamlined shapes to reduce air resistance.