Place your poinsettia in a sunny window.  These plants require bright light - the more, the better.

Keep soil evenly moise at all times.  Even a day without adequate moisture is enough to make poinsettias drop their leaves.

Provide a constant source of humidity by filling an overflow saucer with gravel.  Water seeping through the pot will evaporate from the gravel.

Turn up the heat!  Poinsettias are native to Mexico where it is hot during the winter.

Keep the temperature as close to constant as possible, day and night.  Decreasing temperatures can cause leaves to drop.

Fertilize weekly with half-strength liquid houseplant fertilizer or use a slow-release food when you first bring your poinsettia home.