For every smartphone user this is important that they use a tampered glass for protection of screen and display. And a back cover for avoiding the dust and scretch, mobile cover is really very important from protection the dust and shock.
Make sure the tampared glass is of good quality for proper safety of mobile.
Now comes to earphones , earphones are the thing which can easily damage so handle them very carefully if possible carry a earphones cover.
So these are very little things which can improve your smartphones life.
Thank you.