The worst thing about receiving a bad present is not knowing how to react or look natural when you open it. Christmas Eve is a pretext to stare at the mirror mimicking all your possible reactions. It's a time to practice forced smiles, exaggerated laughs, and the fake 'thank you.'
The most dreaded situation is getting a gift that you just hate, that is not you at all, and in the worst case, doesn't even fit. Well, the first thing to keep in mind is not to panic or start crying. After inhaling some fresh air, stay polite, and focus on the giver's feelings which were focused on the recipients happiness. The best thing is to not even try to explain why this present screams everything you dislike; it would take too long and create drama. Put in practice one of your fake smile, and hide the gift in a drawer. Maybe when you find it in a year you'll be able to laugh or even get attached to it.
The situation that happens most of the time is that you really like the present but it is not perfect. The Cinderella shoe is half a size to small, the dream cashmere scarf is the wrong color, or your pearl necklace is not the perfect length. The reflex one should have is dedramatize the situation. If you know the gift giver well enough, you may be able to get the receipt and exchange it. On the other hand, if the person is a new boyfriend or a best friend, it's best to be polite and pretend you adore it. With a bit of luck, orange will be next season's color.
The most pleasing circumstances are when your Christmas seems like a fairy tale'but let's be realist, it is impossible now that adulthood has been reached and Santa no longer exists.