How to make my iPhone better?

What can I turn off and turn on in the settings to make it better?

What do you mean by better?
What iPhone is it?
What problems do you have with it?
Details details please

Are you talking about making your battery life better? I'd have to know what iPhone you have and what version of IOS it currently has installed on it? If you leave a comment on this question I'll come back and try and answer it for you. You weren't specific enough.

Turn off your iPhone's Wi-Fi when not in use

Turn off your iPhone's Wi-Fi when not in use.

Turn off your iPhone's GPS when not in use.

Turn off your iPhone's Bluetooth when not in use.

Dim your iPhone's brightness when using in night or in low light.

Turn your iPhone's camera flash to Auto Flash.

Its All.