Don't forget the additional half-step at each step of your design:

• Examine each required feature
  • Is there a CPAN module that already does this?

...

• Examine each algorithm or data structure in the program design
  • Is there a CPAN module that already does this?

I know, it's just the obvious "don't reinvent the wheel" line. Still, I get carried away with my own (imagined) cleverness sometimes, and had to make this an official part of my routine. If I don't look for pre-existing modules, I don't get to have any more coffee that day. A little self-imposed discipline there :-)

---

"All you need is ignorance and confidence; then success is sure."-- Mark Twain