Ok, but that sounds too general, though. For example, when I first had unit tests, I felt that my code quality improved greatly. Or after I walked around with

Ok, but that sounds too general, though. For example, when I first had unit tests, I felt that my code quality improved greatly. Or after I walked around with an iPhone at university, and got people to participate in a 5mins usability test for a mobile webapp, I also felt that the end result was on another level. I'm thinking of techniques that will eliminate errors, or make coding faster, or result in a better user experience, etc.