Jumping into preparation without a timetable or study plan will only make a failure in long run.
Continuously studying new material without revisiting older topics will result in no proper retention of topics.
Studying randomly without aligning with the syllabus or analyzing past questions will lead to studying unecessary and unimportant topics which waste your time significantly.
Poor sleep, irregular eating habits, and ignoring physical fitness lead to poor performance in long run.
Delaying important tasks like starting a subject, practicing questions etc., will ultimately lead to overburden at the end.