7/34 First step you can take? Change the #fan setting on your #thermostat from "auto" to "on" (always on). With modern HVAC systems, the #circulation fan is generally pretty efficient; keeping it on uses some #electricity, but #saves more on the heating or cooling demands, so it's a net #benefit.

Modern furnaces will commonly run their fan at a lower speed when not "on cycle", giving you enough air movement but using even less energy to do it.

3/34 First, do the well-known stuff.

Program your #thermostat to only fully warm/cool your house when you're not away at work (if remote-working hasn't changed that calculus for you).

Make sure your doors and windows have good seals and don't let in drafts. Replace your #furnace air filters regularly.