Hiiii

First of all you must be dedicated towards you study.
Since now only few months are  left for your exams you need smart study at this point of time.

Do not waste time unnecessarily, analyse your strong and week parts.
Revise all the topics that you feel you have strong hold on so that you do not need to waste time on them again and again.Try to clear all your concepts and have a clear vision about any topic you have covered. 

Firstly make a schedule of your daily routine and stick to your plan, yes you can make necessary changes according to the need of hour. There’s no need of studying continuously, divide your day in slots of 3-4 hours with breaks in-between, So that both your body and mind remains relaxed and ofcourse efficient.

Remember to give equal time to all the  subjects.
Be honest towards you studies and plan your tasks on daily as well as weekly basis.

Try to solve sample papers and previous year papers regularly so that you get an idea of how the questions are asked in the board exams. 
Do not study till late hours in night,keep your mind and body fresh by engaging in some physical activity.

At last the most imortant thing, Believe in yourself and stay confident. These are just the board exams do not have any fear and study confidently.

ALL THE BEST!!

Here are some preparation tips you can follow for the board preparation:

After completing any topic you should revise it two or three times. So, that you understood that topic completely. You should be aware of the topics which carries more weightage in the exam. So, you can devote more time on that topics.

You should make your proper time-table. So, you get time for proper revision. You can make your own notes it will help you in revision. Solve previous year papers to understand the difficulty level of the exam.

 
Good Luck!