NDA (National Defense Academy) is the best entry point for becoming an officer in the Indian Armed Forces. The tips suggest starting preparation 3-4 months in advance by revising 10th standard subjects and purchasing previous year question papers. Key subjects to focus on are mathematics, English, and general knowledge obtained from reading newspapers. Practice is important, especially for mathematics, and mock tests can help evaluate exam preparation level. Coaching institutes can also help guide preparation and build skills like communication.