I've taken many a certification exam over the years, and helped many others prep for theirs. Here are the five things you must do on exam day to maximize your efforts.

1. Show up on time. Yeah, I know everyone says that. The testing center wants you there 30 minutes early. So why do so many candidates show up late, or in a rush? If you have a morning exam appointment, take the traffic into account. If it's a part of town you don't normally drive in during rush hour, you might be surprised at how much traffic you have to go through. Plan ahead.

2. Use the headphones. Most candidates in the room with you understand that they should be quiet. Sadly, not all of them do. Smacking gum, mumbling to themselves (loud enough for you to hear, though), and other little noises can really get on your nerves in what is already a pressure situation. In one particular testing center I use, the door to the testing room has one setting: "Slam".

Luckily, that center also has a headset hanging at every testing station. Call ahead to see if yours does. Some centers have them but don't leave them at the testing stations. Wearing headphones during the exam is a great way to increase your powers of concentration. They allow you to block out all noise and annoyances, and do what you came to do -- pass the exam.

3. Prepare for the "WHAT??" question. No matter how well-prepared you are, there's going to be one question on any Cisco exam that just stuns you. It might be off-topic, in your opinion. It may be a question that would take 20 of your remaining 25 minutes to answer. It might be a question that you don't even know how to begin answering. Whatever the reason, it's the question that has you thinking, "WHAT??" I have talked with CCNA candidates who got to such a question and were obviously so thrown off that they didn't do well on any of the remaining questions, either.

There is only one thing to do in this situation: shrug it off. Compare yourself to a major-league pitcher. If he gives up a home run, he can't dwell on it. He's got to face another batter. Cornerbacks in football face the same problem. If they give up a long TD pass, they can't spend the next 20 minutes thinking about it. They have to shrug it off and be ready for the next play.

Don't worry about getting a perfect score on the exam. Your concern is passing. If you get a question that seems ridiculous, unsolvable, or out of place, forget about it. It's done. Move on to the next question and nail it.

4. Finish with a flourish. Ten questions from the end of your exam, take a 15-to-30 second break. You can't walk around the testing room, but you can stand and stretch. By this point in the exam, candidates tend to be a little mentally tired. Maybe you're still thinking about the "WHAT??" question. Don't worry about the questions you've already answered -- they're done. Take a deep breath, remember why you're there -- to pass this exam -- and sit back down and nail the last ten questions to the wall.

Before you know it, your passing score appears on the screen!