It is free to conserve power; it costs money to make more power.

• use power at the right time. The best time to use power is when the bank is in Float or well into Absorption charging stage. The worst time to use power is at night when no solar charging is possible, or in Bulk when the battery needs all the current it can get. If you time it right (like in Float) you can use loads up to the max current your panels+controller can pump out¹⁾ without affecting the batteries at all. As long as the controller can hold Vfloat you are not using battery power.
• use 12v gear when possible; avoid inefficiencies associated with inverters
• turn off inverters when not in use to avoid parasitic loads
• use roof fans that have low speeds available, and thermostats that can regulate fan speed and/or operation
• cover up windows to avoid heating from sunlight, leading to less fan use
• upgrade non-LED lighting to LED
• unplug unused devices/chargers
• choose items that power off (no standby mode)