Favorite Pragmatic Software Development Tips

From The Pragmatic Programmer: From Journeyman to Master
See them all here.

• DRY—Don’t Repeat Yourself
  
• Always Use Source Code Control
• Write Code That Writes Code
  
• Design with Contracts
• Refactor Early, Refactor Often
• Abstractions Live Longer than Details
• Don’t Use Manual Procedures
  
• Test Early. Test Often. Test Automatically.
• Use Exceptions for Exceptional Problems
  
• Minimize Coupling Between Modules
• Put Abstractions in Code, Details in Metadata
• Design Using Services
• Separate Views from Models
• Don’t Program by Coincidence
• Test Your Estimates
• Design to Test
• Find Bugs Once
• Build Documentation In, Don’t Bolt It On