Think of or Think about?

You use ‘think of’ to talk about producing an idea.
I have to think of a way to explain this.

When asked for an opinion, ‘think about’ is used.
What do you think about this?

For other uses, you can use either.
I’m not sure what I think of this.
I’m not sure what I think about this.

But ‘think about’ tends to be used for things that require more consideration.
Just think about it.