Coding practice - Keep things simple

• Good readability - Minimize the time it takes for people who understand your code.
• Easy to maintenance
• Easy to understand
• Learn from open sources, for free!  (Rails gem is a good source for Ruby developers.)
• No matter how complex a system be, each module and building block can be kept as simple as possible.
• Each object response for a simple functionality.  
• Each single function can be unit tested.
• Keep method size as short as possible.  Say, 5~10 lines.
• Beautiful code comes from simplicity.
• DRY - Don't repeat yourself.
• Do NOT repeat any single business logic on different methods.
• Before adding a new method or logic, check whether its already implemented in the system.  Reuse or create a wrapping function base on it.