A thin, lightweight cover over your phone's screen can prevent it from shattering if it gets dropped while your kids are playing a game or you're trying to snap shots at a concert. Upgrade to one with an oleophobic coating to shield against smudges and messy fingerprints.
Holding your phone in your hand isn't really an option as you weave your way through traffic. Whether you commute on four wheels or two, a phone mount holds your device steady and allows you to check maps and control media playback without taking your eyes off the road for too long.
Although it won't protect against major damage, a wallet phone case will protect against minor scratches and dribbles of coffee. It'll also keep your phone alongside your cash and cards, so you won't have to search for everything once you're out the door.