once in a while

Then I think, maybe I should every once in a while.

You guys have those every once in a while, it lasts an afternoon.

It is the job of the sports columnist to be ridiculous, to lard on sweaty superlatives and routinely declare the regrettable, but once in a while, we get it right.

They persist because, as George Soros can attest, once in a while they are proven right.

Every once in a while an exhibition catalog turns out to be better than the show it documents.