Never let a diesel run out of fuel. Drain water and sediment from fuel sediment bowl on gasoline engines. Check cooling fins on air cooled engines for dirt and debris. Check coolant level in radiator of water cooled engines. Make sure the percentage of antifreeze in the water is adequate by measuring the specific gravity with a radiator hydrometer.
Some older engines have plugs in place of dipsticks.
Check transmission and hydraulic oil levels if applicable. Check condition of all air intake hoses and system. Check water level and terminals of battery. Check tire pressure and condition. Check for loose bolts and nuts, tighten as required.