Replace the A/C filters
Replace the filters on your A/C once every month. Pick a date and make sure you never forget. Check the number on the filter in the unit, and buy the same size when the time comes to replace it.
Check for debris
After replacing the filter, go to the A/C’s external unit and check for obstructions in the system. Remove any leaves or debris caught in the grate, if there are any. Trim plants that may be blocking airflow to the unit, making sure that there’s a 2ft clear space around it.