You cannot make the unit more efficient, however, you can assist the unit to operate more efficiently by closing doors and windows, using the right sized heat pump / air conditioner, ensuring your filters are clean and that there are no obstructions around the indoor and outdoor unit impeding airflow.
Set appropriate temperature setpoints: setting a slightly lower temperature (1-2°C lower) on heating mode during winter compared to your summer setpoint, and a higher temperature setting on cooling mode during summer (1-2°C higher) relative to your preferred heating setpoint can reduce energy consumption.
The use of timers to schedule the operation of the heat pump / air conditioner can assist in running your unit efficiently.  For example, using the sleep timer when going to bed, or using the on/off and 7 day timers to allow the system to start running in the morning a few hours before you get up, and to ensure the unit turns off when you go to work.