Thinking outside the box is a handy metaphor for changing habits, but without some thought and effort, it’s not going to happen. That’s because your brain needs mental boxes to organize and use what we know. You can’t think without them.
So? Get better boxes. New boxes with different assumptions and parameters.
To start, says the book Thinking in New Boxes, doubt everything, then examine possibilities, try different models, pick the best one and act on it. Re-evaluate constantly.