The best advice for care of both Chistmas Trees and Christmas arrangements featuring Pine and other Christmas Greens is : Water Water Water! Fresh pine drinks lots of water and all fresh Christmas arrangements should have fresh water added daily. Mix the flower food packet with water per the directions printed on it and use this to water your arrangement for maximum longevity.
Fresh flowers prefer to be kept away from direct heat sources like radiators, heat vents and appliances like TVs or refrigerators.
Also, remember when taking any live plants such houseplants and live flowers outside in the winter months they must be wrapped. They should be covered with a bag and the bag tied shut, If your plants or live flowers are not wrapped they will get frost bite and turn brown to almost black in color, and they will shrivel. Flowers and plants are very tender, as humans are, when it comes to the cold. We put on coats and gloves to go outside, then we need to do the same thing for our plants and flowers. Once you get your item into your house simply cut off the bag or sleeve that it is wrapped in and enjoy!