A few things will make life easier.
Assign different ringtones to different contacts, such as your partner, boss, children or school, so you'll know if it's someone important calling before you've even got your phone out of your bag.
When you go on holiday, turn off your voicemail so callers can't leave a message, which you'll be charged for listening to if you're abroad.
To conserve a phone battery, turn the screen brightness down, cloase any apps running in the background that you don't need, and turn off 3G/4G, as these all sap power.
Various sources
