These are the 6 pointers that I used throughout my career, which made it relatively easy for me, and might help you as well, to crack your next big interview.

1. explain your thought process throughout the interview - don’t be quiet
2. start with a relatively simpler solution - not naive
3. ask clarifying questions to understand constraints and assumptions better
4. the interviewer wants you to win, so when in doubt ask for help and hints
5. when confused or about to panic, take a deep breath, and start over
6. write code in a language you are extremely comfortable with

I have personally preferred Python during interviews because it makes it really easy to express your solution quicker through a more concise code v/s going for high verbosity Java or C++ code.

note: some interviews are meant to judge you on a specific language, so clarify this with your interviewer before you jump to the solution.