Sounds obvious now, but don't obsess over abstracting everything in the application ("Oh, I need to create my own authentication system with redundancy and open

Sounds obvious now, but don't obsess over abstracting everything in the application ("Oh, I need to create my own authentication system with redundancy and openid support!") where it's not necessary. I've spent countless hours fumbling over parts of code which weren't really integral to the prototype at all... such as a custom javascript library...