Best way to extend battery life on Android phones?

I've been noticing my Android phone's battery drains super fast lately, even when I'm not doing much. I've tried turning off Bluetooth and lowering screen brightness, but it still feels like it barely lasts half a day. I’m running a pretty standard setup with no crazy apps or games. Has anyone found some simple tweaks or apps that really help extend battery life without turning the phone into a dumb brick? Also, does anyone have experience with battery saver modes - do they actually work or just slow down the phone too much? Would love some tips or personal hacks that have made a noticeable difference!