Take it with a grain of salt

The expression take it with a grain of salt means that you should be a little skeptical about something, especially a piece of advice, or that you shouldn't take it too seriously. Here are a few examples:

We took her warning about the weather with a grain of salt.

It's only my opinion, so you should take it with a grain of salt.

Bob has always disliked Jim, so you should take whatever he says about him with a grain of salt.