[gwbas1c]

1: Simple code is easier to refactor than complicated code. Try to keep your design as simple as possible.

2: It's easier to refactor code with good automated tests, like unit tests, because you can push a button and know that it works.

3: Make sure that your startup order is well-defined. It's easier to debug a well-defined startup order than a startup order where everything is implicit.

4: Know the difference between a design pattern and a framework. Frameworks don't replace knowing how to use a design pattern correctly.

[spaetzleesser]

"2: It's easier to refactor code with good automated tests, like unit tests, because you can push a button and know that it works. "

One thing too keep in mind is that the tests should also be kept relatively simple. I have seen codebases where there were so many and often complex tests that modifying the actual code was easy but changing the test would have been prohibitively expensive.