Clean your filter. If you haven’t cleaned the filter on your air conditioner since last year, it’s costing you more than it should to run it.
Make sure you’re using all your fans. They’re way cheaper to run, so use them to circulate the cold air. And set them to run counter-clockwise in the summer.
Make sure you’re not blocking air vents with furniture. And make sure your thermostat is in a good spot. If the sun hits it or it’s in a room that’s warmer, the A/C will keep running even when the rest of your place is cool.
Stop cooling down rooms you’re not using. If you have an extra bedroom, keep the door closed. And if there’s an air vent in there, keep that closed too.
Keep your blinds and curtains closed. Your air conditioner has to work a lot harder if the sun’s blasting in through the windows.