Reject the culture of lower standards and mediocritization. In the absence of adequate challenges or tests, test yourself. Seek other high performers to test yourself against.
Master the habits of success: tenacity, craftsmanship, self mastery, and true confidence. Practice and train the basic skills: memory, logic & reasoning, mathematics and reading. Combine these with physical exercise in different combinations daily.
Read things you agree with. Read things you don't agree with. But most of all, be critical of what you read.
Engage with others. Learn both to lead and to follow. Respect your elders.