What’s the most natural way to decline to answer personal questions?

For example, if you're wearing a bandage and someone asks what happened, but you don't want to talk about it.

In English, I would probably just say, "Don't worry about it."
But I am assuming that 「心配しないで」wouldn't have the same nuance.

Anyone know the most natural way to brush off personal questions?

I'm thinking just something like「大した物ではありません。」or 「何もないよ。」

Would that work?