Looking back at my career and life as a programmer, there were plenty of different ways I improved my programming skills - reading code, writing code, reading books, listening to podcasts, watching screencasts and more.
My question is: What is the most effective thing you have done that improved your programming skills? What would you recommend to others that want to improve?
I do expect varied answers here and no single "one size fits all" answer - I would like to know what worked for different people.