My first CS teacher in high school required index-card size functions (actually procedures because it was Pascal). It's helped me immensely over the year, becau

My first CS teacher in high school required index-card size functions (actually procedures because it was Pascal). It's helped me immensely over the year, because those 5-10 line functions end up growing into 100 line behemoths as features get added. Starting with smaller bits gives you a longer mean-time between refactorings.