All the syllabus books in any board exam are designed according to the strict syllabus and this has never happened in the history of board exams that a question has come out of the syllabus.
Take out your answer sheets of pre-boards and class tests etc, and take a deep look into your answers, find your mistakes, make a list of those mistakes for each and every subject.
You have to study at least 8 hours a day and make it 9 to 10 hours on holidays like Sunday. This feels like crazy, studying with such madness, but the 90+ achievers did that and made their percentage possible.
Take each and every year question paper seriously and start solving them and feel like you are sitting in the examination hall of board exam.
English can be used as a booster in making a high percentage, all you need to do is to study it, at least, a day in a week. if you can maintain this, then surely this subject will support your percentage in a great way.
Your answer sheet is the only thing on the basis of which you will get your marks, so everything related to your answer sheet matters.
Do each and every question with the same attention and the same focus because each question is important. Use similar writing and formatting throughout the answer sheet.
Don’t be in a hurry to leave the examination hall after completing your exam, wait until the last second of the exam. Cross-check your answer sheet twice, thrice, and again and again.