Find the Bottleneck

Every skill has a bottleneck: one sub-skill or concept that, once unlocked, makes everything else click. In programming, it might be how functions work. In a foreign language, it might be the 500 most common words.

To find it, look at where beginners most often get stuck or quit. Browse forums, read beginner retrospectives, and ask people who recently learned the skill what they wish they had known earlier.