- Focus on good code decomposition
- Learn how to rigorously and systematically debug code
I like the point about using scientific method in debugging code, I also do that.
- Start writing tests
I notice this important point thanks to my senior. He introduced to me the concept of automated testing. I find it important because there are too many things to test and its hard to keep track, instead, code tests into your code and your will remember and it is automated, also saves the work of the tester.
- Have a good sense of craftsmenship
Reddit: What good habits should a beginner programmer start to develop as early as possible?