What are some energy saving tips?

I have recently been trying to cut back on unnecessary spending to keep my monthly bills lower.

I’m trying to save up for a new car at the end of the year and every little bit helps.

One of the suggestions I always see on money saving guides- right after they say to stop spending $6 on a latte every morning (that has never been an issue for me)- is the recommendation that you cut down your heating and cooling bill. I know the usual stuff, set your thermostat to 68 degrees in the winter, don’t run the central air conditioning too much in the summer, etc. I’m looking for big savings, but I’m not in a position to buy a new furnace and central air conditioner with a great SEER (Seasonal Energy Efficiency Ratio) rating- I always see that on the suggestions, but I don’t have the money for that right now and my current furnace and central air conditioner work great! I’m looking for cost-effective energy saving tips. Is there any sort of supplementary heating and cooling that I can install to make it a little smoother? Are there air filters or furnace filters that make airflow more efficient? I’m just looking to save some money. What about smart thermostats? I keep seeing people explaining that their programmable thermostat has saved them a lot of money on their monthly heating and cooling bill. Is there any truth to that? Do you have a smart thermostat? Are smart thermostats easy to use? I appreciate any advice I can get! Thanks.

a/c workman