Check thermostat calibration (improperly calibrated thermostats will result in incorrect temperature in the home).
Clean and check the blower fan to remove buildup of dirt and dust, which reduces the amount of air circulated through your home.
Wash or clean any washable filter.
Check and rinse outdoor coils.
Check all electronics.
Check for proper temperature drop (refrigerant pressures checked when needed).
Check fan control.
Lubricate all moving parts.
Check all electrical wiring to be secure and intact.
Clean and check condensation drain.