Devices can still break even when in a case, but having that sort of protection greatly reduces the probability. Find a case that offers you maximum protection with minimum annoyance. For example, a bulky case that you will get frustrated with then toss aside is of no good to you in the long run.
Read a Book
Many people used to engage in more healthful activities, but find it easy now to just quickly run to their device as a pacifier. Consider turning your phone off for stretches at a time and get into the practice of reading books.
Be Mindful of Consumed Content
Most every song, website, TV program and movie is available on our devices. Some of them are harmless but others have the power to corrupt aspects of our lives and our understandings of reality. Be mindful to let entertainment have the smaller place in the budget of your time and be careful of what you choose to consume.
Activate Automatic Backups
You can replace your phone but you cannot replace your data. Nobody thinks anything will happen to their phone until it does. Turn on automatic backups and pay for extra space if necessary. It is money well spent to protect precious memories and data.
Stop Driving Distracted
Take what steps are necessary to set your vehicle up to reduce the necessity and temptation of engaging with your phone while driving.