Take care of a poinsettia plant by allowing it access to plenty of sunlight, placing it in a location with a steady temperature and not drafts and transferring it to a slightly cooler location during night. Water it only when the soil feels dry to the touch.
Keep poinsettias inside next to a window for as much sunlight as possible, but make sure to keep them away from any drafts. The daytime temperatures need to be between 60 and 70 F with the nighttime temperatures slightly lower from 55 to 60 degrees. Once the soil dries out, water the plant until it seeps through the pot's drainage holes into the plant tray, and then immediately dump out the water in the tray. Feed the plant a few times a month with a water-soluble fertilizer.
After the plant finishes flowering and starts growing shoots in the late winter, trim down the stems until they are only 6 inches tall and snip off all but a few leaves on each branch. As the plant grows, transfer it to a larger pot, and use light potting soil containing peat moss and perlite. You can place the plant outdoors during the day in the summer as long as you water it frequently and bring it inside once the temperature drops.