I don't remember where I saw this, but I pinned this to my pinboard recently. Good advice from 2004 from Uncle Bob:
Take my advice: go well, not fast. Care about your code. Take the time to do things right. In software, slow and steady wins the race; and speed kills.
In my experience, this is difficult to follow. It's always easier to do things quickly, to cut corners, to skip writing tests. And external pressures to do more in less time, to hit deadlines. But the technical debt you are building up is a real thing, and maintenance and productivity suffer greatly. It gets harder and harder to recover, and eventually you settle for mediocrity. To change this takes a real paradigm shift in thinking.