Given an ''if-then-else'' (LookBeforeYouLeap)...

  if happiness
    foo()
  else
    sadness()
  end

...the ''if'' statement's condition and ''then'' block should prefer the HappyPath. The SadPath should only appear in the ''else'' block.

Or perhaps CoupleLeapingWithLooking:

 try {
    foo();
 } catch(Exception e) {
    sadness();
 }