Lay low

'Lay low' is what people tell you to do when you're sick, which means to rest and do as little as possible. However, this is a change-in-progress, because people lie and things lay. But it would sound quite odd to hear a native speaker of American English say, "Lie low."

Example:
-I feel awful. I have a fever, a stuffed up nose and a terrible cough.
-You'd better lay low for the next few days. Hope you feel better!

None of my friends are going.

"None of my friends are going" is a very common mistake in spoken American English; you almost never hear it said correctly anymore.

The correct sentence should be, "None of my friends IS going," because 'none' is the subject and 'of my friends' is a prepositional phrase and therefore not the subject. But Americans usually match the verb to whatever's closest to it, subject or not.

Example:
-Are you going to the dance Friday night?
-I don't think so, Mom. None of my friends are going.