The speaker advises against focusing solely on theory. In the first year of studying, they primarily focused on theory and neglected practice questions. This led to difficulties in applying knowledge, slow problem-solving, and a lack of understanding regarding what exams truly test. The key takeaway is to balance theory with extensive practice exercises.

Another mistake highlighted is pride during exams. The speaker recounts spending over 20 minutes on a difficult physics question in the ENEM 2020, only to find out it was one of the hardest and later annulled. It's crucial to skip challenging questions and return to them later to avoid wasting valuable time and ensure a calmer approach to the rest of the exam.

In the third year of studying, the speaker focused solely on practice questions to the detriment of mental health. They emphasize the importance of taking breaks, spending time with family, and incorporating physical exercise. Maintaining a healthy mind is essential for optimal performance during exams.

The speaker's effective study strategy involved watching video lessons (recommending 'Biologia Total' and YouTube channels like 'Prova Total') and simultaneously reading corresponding textbook or online course material. This dual approach helps in understanding complex topics, as professors simplify concepts, while written materials provide more detail and allow for highlighting and note-taking. Focusing on causes and consequences, especially in humanities, is vital.

For subjects like physics, chemistry, mathematics, and biology, the speaker found success in drawing diagrams and creating visual summaries. For instance, in biology, drawing arthropods with their systems or flowering plants with their parts helped in understanding and recalling information. These visual aids served as effective revision tools.

The speaker prioritized subjects based on their career goals (e.g., Biology, Physics, and Chemistry for medicine in the second phase). They organized their day by period (morning, afternoon, evening) rather than strict hourly schedules. The most important strategy was consistently taking old exam papers. This helps in understanding the exam format and identifying weak areas.

A crucial tool was a 'correction notebook.' After taking mock exams, the speaker would meticulously review each question using resources like 'Gabarito Enem', which provides in-depth explanations for both correct and incorrect answers. They would then note down difficult topics, mistakes made, and areas of insecurity, revisiting these concepts until fully understood. This proactive approach helped predict exam content, as exemplified by topics appearing in ENEM that were revised right before the exam.

The speaker emphasized simulating real exam conditions during practice tests, including time limits, no breaks, and no external help. This builds confidence and familiarizes one with the pressure. Moreover, it's essential to actively address weaknesses, even if it's painful or difficult. Focusing only on strengths will not lead to improvement in critical areas needed for success.

The final and most important message is to be an active and self-directed learner. Instead of passively receiving information, question 'why' things work as they do, like the derivation of mathematical formulas or the explanations behind scientific phenomena. Utilize tools like Google Maps to visualize historical and geographical contexts. This active engagement fosters deeper understanding and problem-solving skills, allowing one to deduce answers even when feeling unsure during an exam.