The best way to prevent drinking and driving is to educate yourself. Start with knowing the facts. The fact to know is, when you drink, it affects your mobility. The dangerous part is it decreases your reflection and reaction and when you are driving it can be too dangerous. If you check the news, you would probably know how many people get killed due to drunk driving. Things can be even worse if your drunken driving will lead to get somebody get killed.
Also, if you think you are addicted to drink and drive, then get a driver for yourself. Also it is important to know whom you hire to drive if in case he also has drunken drive problem, then you should avoid.