Put down your cellphone - don't even think about checking a text message or answering the phone while you're trying to drive!
Remind yourself that you're trying to steer several tons of metal that are speeding down a roadway full of other hunks of metal going even faster than you are - it's like a video game and if you don't watch out, you're going to lose it
Remember that you cannot see everything around you without turning your head to check your "blind spot"
Keep your mind on what you're doing - focus on driving and don't try to think about what's going on somewhere else, or what's on the radio, or what everybody else is saying