Some critics of positive thinking have advised people to discard all happy talk and “get real” by dwelling on the challenges or obstacles. But this is too extreme a correction. Studies have shown that this strategy doesn’t work any better than entertaining positive fantasies.

What does work better is a hybrid approach that combines positive thinking with “realism.” Here’s how it works. Think of a wish. For a few minutes, imagine the wish coming true, letting your mind wander and drift where it will. Then shift gears. Spend a few more minutes imagining the obstacles that stand in the way of realizing your wish.

This simple process, which my colleagues and I call “mental contrasting,” has produced powerful results in laboratory experiments. When participants have performed mental contrasting with reasonable, potentially attainable wishes, they have come away more energized and achieved better results compared with participants who either positively fantasized or dwelt on the obstacles.

This is also useful for goal setting.

It's okay to have big goals, but mix in realistic short term goals, too.

That way you can achieve along the way toward bigger goals.