Poinsettias are native to Mexico. Getting them through the holiday season in good shape can be a challenge. They do best in bright, humid conditions. It's expected that they'll drop leaves. The transition from a humid greenhouse to our dry houses is hard on them. Don't overcompensate by overwatering. That will hasten their demise. Keep your poinsettia plants damp but not soggy. Foil wrapping should be removed or at least cut a hole in the bottom for water to drain. Place the pots in a saucer with pebbles or gravel. The excess water will collect in the bottom. As it evaporates, it will raise the humidity level around the plant. Avoid placing them near a heat vent. Consider using a humidifier. Grouping poinsettias with other plants will also provide group humidity. I use a big, low wicker basket lined with plastic. Any number of houseplants and seasonal plants can be combined with them in pleasing manner. You can read more here: https://www.9news.com/article/life/home-garden/proctors-tips/how-to-care-for-poinsettias/73-0e95f45a-4a6c-43e4-8634-4e37b9d3af9a