Reducing the graphic effects of Windows and macOS is another important trick that you should think about if you want to increase battery life and, why not, also to optimize the performance of your PC (especially if it is an obsolete model).
Have no idea how to reduce the graphic effects? On Windows, open the Control Panel, click on the System and Security item located at the top left and, in the window that opens, click on the System item (which would be the third in the list) and then on the Advanced system settings item it’s in the sidebar on the left.
In the System Properties window, click on the Advanced tab, press the Settings button, go to Performance Options, click on the Visual Effects tab, uncheck the listed effects (e.g. Animations on the taskbar, Dissolve menu items after click, Use drop shadow for desktop icon labels, etc.) and save the changes by clicking on the Apply and OK buttons.