Hello dear, 

Some of the tips that will help you to prepare for your cbse board exams are: 

• Give equal attention to all the subjects as all of them are very important and you have to pass in each subject. 
• Study according to the weightage. Give more attention to hard and important topics
• Study daily and prepare your own notes on it. It will help you alot as a day before exam you can revise from it. 
• Keep weekends for mock trials or sample question papers, do not study on that day just work on your mistakes.
• Avoid listening to music, watching television, text messaging or surfing the Internet while studying.
• Do not study late night and for long hours.
• Eat healthy food.
• Get adequate sleep for at least 6 to 8 hours a day.

All the best!