I generally tend to think of code as "encoding" or formalising intent. If the intent is obvious from the code comments are usually not necessary, but if the intent is hard to decode when glancing at the code, then I comment on it.

Sometimes things are just complicated and they require explaining the intent to help the reader understand the code. It also helps spot bugs or allows someone smarter than me to rewrite it in a better way (for different axes of better)

There are other situations where comments are useful that are covered elsewhere in the thread, too.

So, I've gotten some good ideas on how to improve my code comment etiquette!