Well I recently scored 740 while working full time. In my 1st attempt, I scored 700 and in a month, I was able to increase that score to 740. Here are my top 5 learnings that may help:
1. Nerves play an important role. Try to be calm by practicing deep breathing and just try to focus on the question at hand without bothering about the next questions or the result. Have sound sleep and eat well.
2. Make sure to keep an
error log and analyze the mistakes that you are comitting consistently. These are the easiest to eliminate. Also, you can reattempt your incorrect questions later on to assess your progress.
3. Do not understimate the importance of grammar rules. Simply going by the ear can cost you dearly. Try applying the rules to any material/content that you read anywhere; even at the cost of becoming a Grammar Nazi.

4. Make a schedule. While working, it can be difficult to give time to your job, your preparation and your personal life. Make a plan with timelines and the outcomes you want to achieve and commit to the plan.
5. Appear for official mock exams in the exact same way as you would for the real exam. Any deviations can create a big difference in results. Ofcourse choice of clothes, footwear & pens shouldn't matter. But keep in mind that centres can have strong air conditioning during summers so you may consider getting a sweater. Also, try to avoid drinking a lot of water on the day as your bladder could beg your attention during the exam.
Obviously the exam requires hard work but the exam itself is more tricky than it is tough. The exam will throw potholes that you have to avoid and being attentive during the exam is the key to success.
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