What is the most effective thing you did to improve your programming skills?

curl http://zedshaw.com/dbg.h

The main thing that caused defects was not handling default cases in logic. Things like not filling in the dangling else of an if-statement, not trying to return a value from a function no matter what, and not having a default: in a switch. By always trying to include at least a comment there, or an assert it forces you to think about the logic of the whole statement and prevents bugs galore. Combine that with unit tests and you've got a good solid start.

I don't recommend it because it's an insane amount of work above just writing code. I think it'd be something I'd force on high speed students in a kind of "Boot Camp" situation, but not on anyone else. In fact, I think most programmers couldn't handle having a giant bag of evidence staring them in the face telling them they suck. Also I think most programmers wouldn't get the stats behind the analysis and just keep screwing it up.

I play guitar when I have to think about stuff. I take one to work, and when I'm stuck I bust out my guitar, a pen, and a note pad. I then noodle and practice, and as ideas come into my head I write them down without filtering.

Basically, you need a hobby. :-)

I started in high school writing homework helpers in Java and C++, and writing graphing calculator scripts to make fun patterns. Then I worked with other programmers, and started structuring my code to make it understandable to others. Then I started ACM programming competitions, and learned to rigorously solve problems. Then I found Python, and learned that finishing can be quick and easy. Then I got an internship at a major corporation, and discovered I never want to be an enterprisey programmer. Then I got a GSoC gig and learned to collaborate remotely and make estimates. Then I got a real job and learned to work with code for months and years, instead of churning out small projects, and the importance of finishing early and often. Then I experimented with Lisp, and learned the importance of abstraction, community, and salesmanship. Then I played around with Tornado and started learning about the web. Recently, I got a better job and started learning the importance of testing, the importance of listening to users, and the value of a second set of eyes. Recently, I've started experimenting with the Android SDK, learning the power and limitations of major constraints.

I can't wait to see what the future holds.