alt Hacker NewsHmm, it might be better to just go straight to what leading countries currently do (Finland/Estonia/Japan/Singapore/etc). Other factors probably play a bigger role, like school funding, school autonomy, teacher professionalism (high education level + continuing education + good pay), free school meals/healthcare/transportation etc
One major limitation is the cost. It costs lots of money to train teachers and pay them good salaries. What leading countries are doing currently might not be sustainable for the long run. Cognitive abilities also different greatly from people to people in different discipline. There is no silver bullet.