1. Know what and why you are building. Some would call it business-domain knowledge. I'd prefer calling it "now why your product is being used, and how it is us

1. Know what and why you are building. Some would call it business-domain knowledge. I'd prefer calling it "now why your product is being used, and how it is used exactly". This alone gets rid of the vast majority of bugs and other problems. 2. I used to be a QA for about a decade in a previous life. I know where and how classic (technical) bugs happen, it's easier to avoid then that way.