Some important things which I must tell you are to follow.

1. Work Hard

This is the best and the most important tip anyone can give you. You must not give up in these two years. There will be many ups and downs in these two years. But you must remember that you will reach your destination if you don't give up. My best friend in class 11-12th was not very good at studies and did not perform well. But he kept on working and finally made it to an IIT. There can be no substitute for hard work.

2. Be consistent

When you go to your coaching class, your teachers would be giving you some homework. Solve it on a daily basis. Do not rest before you solve it or before the day is over. Put your maximum effort. Same applies to tests. Try to solve the test to your fullest capabilities without worrying about the marks. Sit for the full length of the paper. Try to solve all the questions you could not solve during the test when you reach home. When in doubt consult the solution and solve the questions again without looking at the solution. Be consistent throughout your journey, and you are done.

3. Ask doubts

Get your doubts cleared. Do not hesitate to consult your teachers or friends when in trouble. Contact family, friends, and teachers when underconfident. Academic doubts must be asked to teachers as and when you have them. Doubts can be dangerous if accumulated. Have a few helpful friends who can clear your doubts. But you must first put your maximum effort in solving the questions.

4. Focus

No hangouts, relationships, parties, social media, mobile phones, PC games, TV, etc. You should be focused on your goals. Everything in moderation is OK, but do keep your priorities sorted. Have a good friend circle.

5. Study Material

For those who are enrolled in a 'good' national/reputed local coaching, your coaching material must be your bible. First finish it twice(solving and then revise). Then move on to these-

Must solve books-

Physics- 1.Anyone of HCV/Resnick Halliday/University Physics
2. NCERT
3. Previous 40 years IITJEE Physics papers, chapterwise

Mathematics- 1. NCERT
2. Previous 40 years IITJEE Mathematics papers, chapterwise

Chemistry-1. NCERT(MUST)
2. Previous 40 years IITJEE Chemistry papers, chapterwise

Books for more problems-

Physics- DC Pandey New Pattern Problems in Physics, Deb Mukherjee Objective Problems in Physics, DLP/class room material of a good coaching.

Mathematics- Subjective problems by A Das Gupta, Arihant Skills in Mathematics Series, DLP of other coachings.

Chemistry- P. Bahadur Problems in Physical Chemistry, Solomons and MS Chauhan Organic, and OP Tandon(for problems), and DLPs as always.

Books for Olympiads/very good rank Irodov, Krotov in Physics, SL Loney(triginometry and Coordinate Geometry) for mathematics, and JD Lee, Paula Bruice for Chemistry. You must solve the Advanced Level questions of your coaching sheet too. Leave no stone unturned for this.

First get reviews from people and Internet and then chose which books to consult and which not.

If you don't go to coaching, better order a DLP from a good Coaching, or use books like Arihant Skill in Mathematics, etc. in Physics and Chemistry(easily available in Market) to prepare, and be regular. Joining an offline/online test series will always help.

Remember that your input matters more than books or coaching.

6. Difference creators-Holidays

Many students tend to waste their holidays(summer break, Diwali break, etc.) Use that time well. We hardly get free time in these two years. It's not wise to waste it. Try covering backlogs in this time. Make a diary, write down what all you have in your mind and put it down in your diary. Make a schedule and follow it. Make sure that basic backlogs are removed first and then move on to advanced ones. These breaks can make a huge difference.

Finally, I would like to say give a lot of tests and exams and put your best effort. This journey is very memorable, and make sure the memories turn out to be good.

You can also check out this app I made for helping JEE/NEET/Olympiad/KVPY/NTSE aspirants with courses, notes, blogs, and much more- AcadBoost

All the best!!!