Keep your potted Christmas tree moist but not too moist. A saucer under the tree will collect excess water and provide a small amount of water for the tree to use between waterings. Try to limit the length of time the tree stays indoors, a few weeks should be sufficient.
Pine trees are naturally very hardy plants. Just be careful not to overwater it, as its roots could rot.
It is also not a fan of dark rooms, so avoid leaving it too many hours a day without light, either natural or artificial.