Before the test, avoid reading or discussing a topic you haven’t touched before. Don’t let the fact that you ‘don’t know it’ affect your mood. Have confidence in your preparation – and think positively, telling yourself that you can make the grade.
 
Time management is critical. Don’t give too much or too little time to a problem. “Don’t spend too much time on a difficult question, so that you don’t panic,” says Banerjee. “Keep things simple. There’s a chance of making an error, especially in the English section. Some questions might be trickier, so read them carefully and calmly.” 

While taking the test, if there is a glitch in the system, don’t worry. If others are not affected, don’t disturb them and ask the centre staff for help. Remain calm.
Sleep on time so that you wake up refreshed on D-day. It would help if you have been studying for the test during the time of day when the actual test is slotted.
Another helpful practice is to visit the test centre in advance to be familiar with the location and route. If you have not done so yet, there’s still some time to do the needful.