To comment or not to comment?

I recently had a quick look at the first blog post I ever wrote, Should you write comments?. This triggered me to question whether I still take the same stance around comments that I did when I wrote the post (over two years ago now).
I am not 100% sure where I stand now. I still think that pretty much everything I wrote is what I do nowadays. But, I think there are a few more situations now where I am willing to use comments.
While I spend a bit more time thinking about this myself, I think it is worth seeing what you all believe when it comes to writing comments. Maybe then, I can better collate my thoughts and possibly write a follow-up post that documents what I do now and what caused me to change my opinion.
So, should you write comments?
If so:

When do you write them?
What do put in them?
Where do you put them?
Do you think you can write too many comments?
Are there times/projects where comments are more important?

And if not:

Why not?
What do you do instead?
Are there times where you have been tempted to write comments