Whenever possible, use indirect lighting for your decorations. Open flames and candles may not be used as decorations in the workplace. When using live evergreens at home, select a fresh tree. One freshness test is to lift the cut tree a couple of inches off the ground and bring it down abruptly on the stump end. The outer needles should not fall off in substantial numbers.
Inner needles do turn brown and shed naturally each year.
When a tree is first cut, a seal of sap occurs naturally over its stump to keep moisture in. It's important to break that seal to allow the tree to take up water needed to keep it fresh during the holidays. Cut trees should be placed in at least a one gallon container of water. Add water daily as needed. A considerable slow down of water intake will occur after two or three days.