Asking good questions
For me it's never really about asking good questions or even asking the right questions, but rather asking questions to begin with when I run into issues. A good example is a challenge I had just completed regarding debugging Ruby code for validating that a triple of numbers could form a Euclidean triangle. The bugs that were in the code itself were easy to find; however I kept assuming incorrectly that the bugs were only in the code and not in the associated RSpec requirements file. Thus when a minor error produced unexpected results, I continued to search the code for hours trying to find a problem that wasn't there to find and it wasn't until I started looking at another's solution that I found the problem. Had I asked if the RSpec file was perfect early on, I would have saved a lot of time.