Criteria first

If you write the test after you've written the code, it's much more likely that you'll write the tests that will pass what you've written.

That's just how our brains work.

If you determine the criteria for whether a decision is good after you've already made the decision, it's much more likely that you'll create criteria that justifies the decision that was just made.

That's just how our brains work.

Determine how to assess whether something is good before you implement it and/or before you make a decision.  Otherwise, you will tend to be emotionally attached to what you just did, what you just decided.