We all need to concentrate at times. And it doesn't have to be hard to concentrate, once you know what you're doing.

http://hypnosisabc.com/go/concentrate

0:18 Drink more water. Because if you're properly hydrated you'll find it a lot easier to concentrate and focus.
0:48 Use the Pomodoro technique: work for 25 minutes then give yourself a 5 minute break. It's a nicely productive way to get more done without stressing out about it.
1:19 Close Facebook, emails, Kik and all those other instant distractions. Because they are distractions and excuses not to concentrate
1:48 Listen to a hypnosis track like the one linked below. The occasional half an hour listening session will pay for itself hand over fist with increased concentration and focus.

http://hypnosisabc.com/go/concentrate